Third seed Gilles Muller struck eight aces and lost five of his first service points to defeat wild card Pedro Sousa 6-3, 6-2 in 67 minutes on Thursday at the Millennium Estoril Open. He will next face qualifier Bjorn Fratangelo or Taro Daniel in the quarter-finals.

Fourth seed David Ferrer, who has 696 match wins, makes his debut at the ATP World Tour 250 tournament during the night session against fellow wild card Frederico Ferreira Silva.

The President of Portugal, Marcelo Rebelo de Sousa, watched the action on day four.

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Spaniards Scrape Into Doubles SFs

Spaniards Nicolas Almagro and Guillermo Garcia-Lopez scraped into the semi-finals by beating fourth seeds Leander Paes and Marcelo Melo 7-6(2), 4-6, 10-8 in one hour and 39 minutes. Paes and Melo recovered from a 2-4 deficit in the second set.

Third seed Diego Schwartzman is still in contention to defend his crown at the TEB BNP Paribas Istanbul Open, advancing to the quarter-finals on Thursday with a convincing 6-1, 6-3 win over Jordan Thompson.

The Argentine didn’t drop serve and broke Thompson four times to reach the last eight in one hour and 21 minutes. Schwartzman has been impressive on the clay so far this season, reaching the quarter-finals at the Monte-Carlo Rolex Masters.

“I always like to be in Istanbul. It’s my third time here and I always play really well,” said Schwartzman. “I don’t know why, but I always have a lot of confidence on this Centre Court.”

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Awaiting him is Dusan Lajovic, who rallied to defeat Mikhail Youzhny 3-6, 6-0, 6-3. The Serbian is through to his first ATP World Tour quarter-final of 2017, but also produced an impressive result in March by coming through qualifying to reach the fourth round at the BNP Paribas Open.

“I had a lot of opportunities in the first set, but I kept calm after and started playing more aggressively from the baseline,” said Lajovic. “I’ve lost in three sets the past two weeks, so this week gives me a lot of confidence. I’m eager to play against Diego tomorrow.”

Lajovic improves his FedEx ATP Head2Head against Youzhny to 2-0. He also leads his FedEx ATP Head2Head with Schwartzman 1-0, scoring a 2015 Davis Cup win for Serbia in their quarter-final tie against Argentina.

Fellow Serbian Laslo Djere continued his rich run of form by defeating fourth seed Paolo Lorenzi 6-4, 6-3. The 21 year old, who received special exempt status into the main draw after reaching the semi-finals last week at the Gazprom Hungarian Open, broke Lorenzi twice in each set to secure the win in 77 minutes.

“I started to play really good this year in Marrakech and have kept going since then. I had a tough pre-season and worked a lot, so I knew it had to pay off,” said Djere. “I’m motivated on the court now and have confidence, so I feel I can beat anybody.”

Next up for the World No. 153 in the Emirates ATP Rankings is another Serbian in fifth seed Viktor Troicki, who defeated #NextGenATP Russian Karen Khachanov 6-4, 7-6(5). Troicki saved a set point on his serve at 4-5 in the second set before eventually wrapping up the win. Troicki now leads his FedEx ATP Head2Head against Khachanov to 2-1, with both wins coming this year. 

DOUBLES

Czech duo Roman Jebavy and Jiri Vesely are through to the semi-finals after defeating second seeds Santiago Gonzalez and Dominic Inglot 6-2, 1-6, 10-4. They’ll play Aussies John-Patrick Smith and Thompson, who needed just 55 minutes to ease past Hans Podlipnik-Castillo and Andrei Vasilevski 6-1, 6-3.

#NextGenATP Korean Hyeon Chung recorded the biggest win of his career on Thursday when he knocked out World No. 16 Gael Monfils in a rain-interrupted encounter at the BMW Open by FWU.

Chung, currently No. 78 in the Emirates ATP Rankings, followed on from last week’s run to the Barcelona Open Banc Sabadell quarter-finals with a 6-2, 6-4 victory over Monfils, who had been attempting to record his 400th match win. Play was suspended due to rain with Chung leading 6-2, 3-3, leading to a 90-minute delay.

“I’m so happy as it’s the biggest win of my career,” Chung told ATPWorldTour.com. “It was a tough match against Gael and I tried to stay calm all the time. The rain delay was tough, but it’s the same for all the players. I tried to keep the rallies long, as this is his first tournament on clay. I will be ready for tomorrow and I will keep trying my best.”

Monfils, a winner of six ATP World Tour titles, will now look to the Mutua Madrid Open in his bid to become the 17th active player with 400 victories, joining fellow Frenchmen Richard Gasquet (468), Gilles Simon (412) and Jo-Wilfried Tsonga (405). The 20-year-old Chung will challenge 2014 champion Martin Klizan, who cruised past sixth seed Mischa Zverev 6-2, 6-1.

“He played a really solid match and he was better than me,” said Monfils. “It’s good to be back on the court, rather than practising. It wasn’t easy and I had a lot of mis-hits, but Hyeon pushed me a lot and it was good to be back playing again.”

Earlier in the day, Horacio Zeballos continued his rich vein of form in a big-serving encounter with fifth seed Philipp Kohlschreiber. Zeballos, who reached last week’s Barcelona Open Banc Sabadell semi-finals (l. to Nadal), saved all three break points he faced to overcome the three-time champion 7-6(5), 6-4 in one hour and 39 minutes for a place in the quarter-finals. Zeballos, who is competing in his 15th tournament of the 2017 season, hit eight aces to 13 for Kohlschreiber, the 2007, 2012 and 2016 titlist.

Zeballos will now face qualifier Guido Pella, currently No. 158 in the Emirates ATP Rankings, who won 28 of his 34 first service points to beat 2014 runner-up and fourth seed Fabio Fognini 6-3, 6-2 in 77 minutes.

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In-Form Team Oust Top Doubles Seeds

Brian Baker and Nikola Mektic, winners of ATP World Tour doubles titles in Memphis and Budapest this year, combined to lose just six of their first service points in a 6-3, 6-4 victory over top seeds Oliver Marach and Mate Pavic. Fourth seeds Julio Peralta and Zeballos booked a spot in the semi-finals by beating Mikhail Kukushkin and Sergiy Stakhovsky 6-7(4), 6-4, 10-5 in just over 90 minutes.

The Top 10 are under siege.

As a collective unit, they are not enjoying the same success this season as they did last year when attempting to win the opening point of their service games.

An Infosys ATP Beyond The Numbers analysis of the current Top 10 in the Emirates ATP Rankings uncovers an almost two percentage-point drop in the Top 10 forging ahead to 15/0 compared to falling behind 0/15 when serving.

In fact, eight of the current Top 10 players are performing worse during the opening point of their service games this year compared to last year. The standout is current World No. 5 Rafael Nadal, who has improved almost five percentage points in 2017 compared to 2016.

The 30-year-old Spaniard is 29-5 through the first four months of this season. The left-hander claimed his 10^th title at both the Monte-Carlo Rolex Masters and the Barcelona Open Banc Sabadell last month.

Read More: Nadal Wins 10th Barcelona Title

The only other player to be in positive numbers in 2017 compared to 2016 is No. 7 Kei Nishikori, who has improved by almost two percentage points.

Top 10 2017 vs. 2016: Percentage of Winning The Opening Point On Serve

The peak performer in the current Top 10 in 2017 is Roger Federer, who is winning the opening point of his service games nearly 69 per cent of the time, with Nishikori in second place at about 68 per cent.

Federer was actually at 73 per cent last season – second to only Milos Raonic, who was head and shoulders above the pack at 74.5 per cent. Nadal was the worst performer out of the current Top 10 during the 2016 season, winning the opening point of his service games only 61.4 per cent of the time.

Navigating from love-all to 15/0 is more challenging so far this season for the Top 10 – a small chink in their armour where opponents are enjoying increased success.