Grigor Dimitrov was eager to avoid a late-night marathon at the Australian Open on Saturday, dispatching 18th seed Richard Gasquet 6-3, 6-2, 6-4 in two hours and two minutes to advance to the fourth round.

After Rafael Nadal’s five-set victory over Alexander Zverev extended the day session on Rod Laver Arena, Dimitrov and Gasquet didn’t get underway until 11:58 p.m. local time in Melbourne. The seventh battle between two of the more majestic one-handed backhands on tour would go the way of the Bulgarian in convincing fashion. He fired 48 winners, including 11 aces, while turning aside six of seven break points faced. He continued his impressive start to the season, remaining undefeated (8-0) after lifting his fifth ATP World Tour trophy in Brisbane two weeks ago.

The lead changed hands early in the first set, but a break to love for 5-3 gave Dimitrov the decisive advantage. He would escape a 0/40 hole in the next game and eventually closed out the opener on his fourth set point. Dimitrov was off to the races from there, breaking immediately to open the second set and once again in the seventh game to take a commanding two-set lead.

A rifled backhand winner and Gasquet unforced error would hand the 15th seed the lead in the opening game of the third set and he did not look back, securing the victory at exactly 2:00 a.m. on his second match point. The record for latest finish at Melbourne Park is 4:33 a.m., set by Lleyton Hewitt and Marcos Baghdatis in a 2008 third-round thriller.

“Lately I’ve been struggling with my sleeping and going to bed late, so this is great,” Dimitrov joked. “It’s my first win on this court so I’m embracing this moment. Thanks to all the fans who stayed here.

“A match like that, it helps me. It helps me to have more confidence, to feel better on the court, more secure in my shots. Just a lot of positives. I take a lot of positives out of that match. The first couple of matches were so-so in my opinion. To be able to come out tonight and step up against a player like Richard, it means a lot to me and gives me good credit. At the same time I just need to focus now, just need to keep the same line, just control what I can.”

It was Dimitrov’s second straight victory over Gasquet, having most recently prevailed at the Shanghai Rolex Masters in October. The Frenchman had previously won their first five FedEx ATP Head2Head encounters from 2011-15.

Dimitrov will feature in the Round of 16 at the Australian Open for the third time in four years. His best finish came in 2014, when he upset Milos Raonic en route to the quarter-finals (l. to Nadal). He will look to match that result with a win over wild card Denis Istomin on Monday. It will be just their second encounter.

Istomin continued his dream run in Melbourne by reaching the second week here for the first time in 11 attempts. Two days after his monumental five-set win over second seed and two-time defending champion Novak Djokovic, the wild card prevailed 6-4, 4-6, 6-4, 4-6, 6-2 over Pablo Carreno Busta.

“It was mentally tough because after beating Novak I didn’t want to lose three sets in a row, and then everybody saying that I’m was too tired,” Istomin said. “I recovered well. I was ready for the match. I think I played good, as well. The conditions were different. The centre court is much slower than that court. So my return wasn’t working like with Novak. Carreno Busta is a big server. But in the end I’m happy to win.”

Istomin fired 16 aces and 51 winners throughout the match, but was most impressive with his stamina. He still looked fresh deep in the fifth set while the Spaniard appeared tired from the hours of long baseline rallies. Istomin raced through the final four games of the match, converting his second match point on a backhand error from Carreno Busta.

The 30 year old from Uzbekistan will aim to reach his maiden Grand Slam quarter-final against Dimitrov.

“With Grigor, I think I beat him when he was like 17 in a Challenger,” Istomin added. “It was a tough match. But I lost to him in Shanghai [in 2014]. He’s been in the Top 10 so I will try to play like I played with Novak and today, and we will see.”

Alexander Zverev had Rafael Nadal on the ropes again. The 19-year-old German led the Spaniard two sets to one on Saturday during their third-round match at the Australian Open.

But for the second time in the past 11 months, Nadal rallied to come back against Zverev, sending the #NextGenATP star home after a 4-6, 6-3, 6-7(5), 6-3, 6-2 win that lasted more than four hours.

Zverev, however, felt positive about the performance. “Even now I’m disappointed, but I know that this was a great match. That was a great fight. There are a lot of positives in this match. I think he’s probably one of the fittest tennis players in the history of the game,” Zverev said. “Obviously I wanted to win. I could have won. It’s disappointing. But I’m fine actually.”

Zverev was trying to reach the fourth round of a Grand Slam for the first time. The 24^th seed was also looking to earn his fourth consecutive win against a Top 10 opponent. In September, he beat then-No. 3 Stan Wawrinka and then-No. 9 Tomas Berdych en route to his first ATP World Tour title at the St. Petersburg Open. Two weeks later, Zverev outlasted then-No. 10 Dominic Thiem at the China Open in Beijing.

Read Match Report: Nadal Survives Zverev In Melbourne

Zverev had been even closer to beating Nadal last year at the BNP Paribas Open, the first meeting of their FedEx ATP Head2Head rivalry. Zverev held a match point against Nadal but eventually fell 6-7(8), 6-0, 7-5 to the left-hander from Mallorca.

“I am close. I kind of showed it a few times last year, and this now,” Zverev said. “We played for over four hours. It was not an easy match. There are a few things here and there I could do better. All in one, I think I’m pretty happy with my performance.”

Reaching the third round is Zverev’s best result Down Under. He fell in the first round to Andy Murray last year during his main draw debut. In 2015, Zverev lost in the first round of qualifying.

The 6’6” right-hander figures to be a top contender at another big event this season, the inaugural Next Gen ATP Finals, to be held 7-11 November in Milan, Italy. The top seven players in the Emirates ATP Race To Milan will qualify; the eighth player will be chosen by wild card.

“I absolutely love tennis. I absolutely love the process. It’s exciting for me,” Zverev said. “I think I can see how I’m getting better. I can see how I’m getting better in five sets. It’s exciting. I think it’s going to be an exciting year for me.”

The home nation will be well-represented in the third round of the Australian Open doubles draw, as Sam Groth and Chris Guccione stunned 10th seeds Treat Huey and Max Mirnyi 7-6(10), 7-6(5) on Saturday at Melbourne Park. The unseeded duo, winners of two ATP World Tour titles together, join the Aussie wild card teams of Marc Polmans/Andrew Whittington and Alex Bolt/Bradley Mousley in the Round of 16.

Groth and Guccione needed just under two hours to move on, launching 17 aces, while saving all three break points faced. For Groth, it is the 29 year old’s third straight appearance in the doubles Round of 16 at Melbourne Park, having advanced as far with Eric Butorac in 2015 and Lleyton Hewitt last year. The Aussies will face Marcus Daniell and Marcelo Demoliner next, after the Kiwi-Brazilian pair stunned sixth seeds and ATP Finals runners-up Raven Klaasen and Rajeev Ram 6-1, 7-6(4).

Also advancing to the third round at Melbourne Park were top seeds Pierre-Hugues Herbert and Nicolas Mahut. The reigning Wimbledon champions made quick work of Jerzy Janowicz and Marcin Matkowski 6-3, 6-2, setting a date with 16th seeds Dominic Inglot and Florin Mergea. Six-time champions Bob Bryan and Mike Bryan, seeded third, also needed just over an hour to prevail on Saturday. The American twins downed Nenad Zimonjic and Mischa Zverev 6-3, 6-2.

Fifth seeds Feliciano Lopez and Marc Lopez set an all-Spanish third round clash against US Open finalists Pablo Carreno Busta and Guillermo Garcia-Lopez, defeating Jonathan Eysseric and Fabrice Martin 6-4, 6-4. The Spaniards advanced after 73 minutes, converting three of six break chances.

Rounding out the Round of 16 field were seventh seeds Lukasz Kubot and Marcelo Melo, 6-4, 7-6(3) winners over Nicholas Monroe and Artem Sitak, as well as the Colombian power of Juan Sebastian Cabal and Robert Farah, who rallied past Serbians Dusan Lajovic and Viktor Troicki 2-6, 7-5, 6-0.

Rafael Nadal survived a marathon third-round battle against Alexander Zverev on Saturday at the Australian Open in Melbourne, coming through with a 4-6, 6-3, 6-7(5), 6-3, 6-2 win on Rod Laver Arena.

“It’s obviously an important result for me,” said Nadal, who had lost his past three five-set contests in Grand Slam action. “So it’s important for me to win a match like this, having been down two sets to one. I’m very happy.”

A single break of serve was all that was needed in each of the first two sets. Neither player faced a break point in the third set, ultimately forcing a critical tie-break. Nadal gave the crucial mini-break to Zverev with a forehand error at 5/5, and the German took advantage by hitting a backhand winner on set point to earn a commanding lead.

But Nadal refused to go away. He raced out to a 3-0 lead in the fourth set and appeared to finally wear down Zverev with the long baseline rallies that highlighted the match. The young German hit 12 winners to 16 unforced errors in the fourth set while Nadal shored up his game considerably, holding onto the lead to force a deciding set.

The final stages of the match ultimately came down to fitness, with Zverev appearing to cramp at 2-2 in the fifth set. Sensing his opportunity, Nadal sprinted through the final four games of the match to prevail in four hours and five minutes.

Nadal improves his FedEx ATP Head2Head rivalry with Zverev to 2-0, having last defeated the German at the ATP World Tour Masters 1000 event in Indian Wells in 2016, saving a match point.

“It was a tough match,” reflected Nadal. “He’s a player that has an amazing potential. He is able to produce great shots. He’s already one of the best players in the world. He can be even better. He can be fighting for the most important things. So I think he will do it.

“For the confidence, for lot of things, it is very important to win these kind of matches. I worked a lot during all of December to have the chances to compete well in these kind of moments. Even if I started the match with some nerves, I think I was able to came back well.

“Mentally I have been very positive during the whole match. In terms of physical performance, I felt great, ready for run for every ball. In terms of level of tennis, I think I finished the match playing much better than how I started the match. That’s a very important thing.”

Nadal goes on to face sixth seed Gael Monfils, who recorded a 6-3, 7-6(1), 6-4 victory over Philipp Kohlschreiber in just under two hours. Monfils has dropped only one set in reaching the last 16 and will look to overturn a 2-12 FedEx ATP Head2Head record against Nadal when the pair meets on Monday. Monfils’ last victory over Nadal came five years ago in Doha.

The 30-year-old Monfils is looking to reach a second successive Grand Slam quarter-final, after making the semi-finals at the US Open in New York, where he lost to Novak Djokovic.