Jared Donaldson and Tommy Paul are off to the perfect starts in their respective 2017 Citi Open campaigns. The 20-year-old NextGenATP Americans ground their way through first-round clashes on Monday in contrasting fashion.

Donaldson, the world No. 69 in the Emirates ATP Rankings and seventh in the ATP Race to Milan, prevailed in a tight 6-7(6), 6-4, 6-3 result over Israel’s Dudi Sela. Paul, who reached his first ATP World Tour quarter-final last week as a qualifier in Atlanta, led Casper Ruud 3-6, 7-5, 3-0 before the Norwegian retired with headaches and dizziness due to dehydration. 

Donaldson dropped just seven points on his first serve and saved four of five break points faced against Sela. He will next meet lucky loser Marc Polmans. The Australian received a first-round bye after John Isner withdrew due to a right knee injury.

Paul surged 14 spots to No. 20 in the ATP Race to Milan with his run in Atlanta last week. It was his first meeting with fellow NextGenATP player Ruud. No. 7 seed Lucas Pouille is next.

A viral illness denied Stefan Kozlov the chance to make it a three-from-three start for the NextGenATP Americans on Monday. Qualifier Yuki Bhambri, of India, led 7-5, 2-0 before Kozlov called it quits. Defending champion Gael Monfils awaits.

It happened quietly, without the publicity of a big win or a breakthrough. But last month and again last week, Juan Martin del Potro reached his highest Emirates ATP Ranking – No. 30 – since October 2014, months before del Potro would sit for the majority of another season because of wrist injuries.

But to del Potro, the ranking didn’t symbolise that his comeback from wrist injuries in 2014 and 2015 was complete. At the Citi Open this week for the fifth time, the Argentine is simply glad to be back on the court.

“I don’t care if I’m 30 or 50. I just want to play tennis,” said del Potro, who, 17 months ago, was No. 1,045. “I would like to be in the top position for sure one day in the future but I know how difficult it is… I’m still playing tennis and I love what I do. I’m so happy for that.”

The 6’6” Argentine might be No. 1 if he played all of his tournaments in Washington, DC. Del Potro has won the ATP World Tour 500 tournament three out of the four times he’s played here. The right-hander beat Serbian Viktor Troicki for his first title in 2008 and knocked out a pair of Americans – Andy Roddick and John Isner – in 2009 and 2013.

He enters this week with a 14-1 record in Washington and on a 14-match tournament win streak. His only loss came in 2007 when he was 18.

“I like to play here… I always play good tennis in the United States,” said del Potro, the 2009 US Open champion. “This tournament is special for me because I have many Argentinean fans who come to watch me. The American people like my game, too.”

He will have plenty of competition at the Rock Creek Park Tennis Center this week. The field showcases four former champions, including del Potro, Milos Raonic (2014), Kei Nishikori (2015) and Gael Monfils (2016). Eight of the Top 25 are also playing here: No. 7 Dominic Thiem; No. 8 Alexander Zverev; No. 9 Nishikori; No. 10 Raonic; No. 11 Grigor Dimitrov; No. 19 Jack Sock; No. 20 Nick Kyrgios; and No. 22 Gael Monfils.

“I think this will be almost a [Masters] 1000 tournament,” del Potro said. “It will be a really interesting tournament to watch and to play.”

Last October, del Potro won his first ATP World Tour title in 33 months by beating Jack Sock at the If Stockholm Open. But the 28 year old has yet to reach a final this season. Del Potro reached the Delray Beach Open semi-finals in February before falling to then-World No. 4 Milos Raonic.

Six of his eight losses this season have come against players ranked inside the Top 6 of the Emirates ATP Rankings, including five against three of the Big Four – Andy Murray, Novak Djokovic and Roger Federer. But del Potro said he’s glad that he’s playing in the same era as the all-time greats.

“The guys are amazing,” del Potro said. “I’m so happy to be playing at the same time.”

Tommy Haas and wife Sara Foster kicked off the German’s last appearance in Kitzbühel in traditional Austrian style, donning Tyrolean outfits in front of Wilder Kaiser on Monday ahead of the Generali Open.

“I’m happy to be back in Kitzbühel. This is the paradise of the Alps,” said Haas. “I always enjoy coming back here. I’m looking forward to my last tournament here and hope that I can play well.”

Thomaz Bellucci, a winner of four ATP World Tour clay-court titles, held his nerve in a thrilling 6-2, 5-7, 6-4 victory over Alexandr Dolgopolov, who was making his debut in Kitzbühel. Dolgopolov led 3-2 in the deciding set, but could not convert two break points on Bellucci’s serve at 15/40. The Brazilian then broke for a fourth time in the penultimate game and will next challenge a German in sixth seed Jan-Lennard Struff or Haas.

Joao Sousa was solid on serve hitting nine aces and saving six of seven break points to beat former World No. 8 Mikhail Youzhny 7-6(4), 5-7, 6-3 in two hours and 13 minutes. Youzhny recovered from a 2-5 deficit in the second set, but was broken to 15 in the 12th game. Sousa now meets third seed and defending champion Paolo Lorenzi, the recent Plava Laguna Croatia Open Umag runner-up (l. to Rublev).

Dusan Lajovic needed one hour and 57 minutes to edge past Maximilian Marterer 7-5, 7-6(4) for a Kitzbühel second-round clash against fourth seed Gilles Simon.

Another Serbian, qualifier Miljan Zekic, recorded his first ATP World Tour match win by beating Andrey Kuznetsov 7-6(4), 7-6(6), closing out on his fourth match point opportunity. The 29 year old will now prepare to face second seed Fabio Fognini, who lifted his fourth trophy on Sunday at the J. Safra Sarasin Swiss Open Gstaad (d. Hanfmann).

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It was one of the more incredible comebacks of the year on the ATP Challenger Tour. Jordan Thompson had one hand on the trophy at the Levene Gouldin & Thompson Tennis Challenger, but Cameron Norrie pried it away from the Aussie in dramatic fashion.

The 21-year-old Brit, at No. 221 in the Emirates ATP Rankings, stormed back from a 1-4 0/30 deciding-set deficit to upset top seed and 86th-ranked Jordan Thompson for his first Challenger crown. Norrie, who would take the match 6-4, 0-6, 6-4, had dropped five consecutive service games in the second and third sets. A double fault put him to within two points of falling behind 5-1 in the decider. But the former Texas Christian University standout exhibited his great resilience, reeling off five straight games to take the title.

Norrie is the third player from Great Britain to win the Binghamton title, joining 2005 champ Andy Murray and 2015 titlist Kyle Edmund. The win also moves to the nation to 4-0 in Challenger finals this year, with Aljaz Bedene earning three titles from three finals.

Norrie, who rises 76 spots to a career-high No. 199 in the Emirates ATP Rankings, spoke about his breakthrough week…

You got broken five straight games and were down 1-4 0/30. Where’s your head at that moment?
I was completely down on myself. I turned to my coach Facu (Facundo Lugones) and was thinking that I just couldn’t do it. He quickly told me to fight and dig deep. Treat it like another college tennis match. I’ve had so many tight matches in college where I’ve fought back. I tried to get my serve in and absolutely battle. I felt like there was no one mentally tougher than me this week. At 4-1 down, I started putting a little more spin on my first serve and it fell in. I was serving better and better and found a lot more confidence from that. I was winning the longer rallies and managed to get over the line. I’m really, really happy to get my first title.

He was trying to pull you off the court with his cross-court backhand and it was hard for you to find a rhythm. It looked like you were able to control more points as the third set went on. What changed?
I felt like he stepped off the gas a little bit and I just stayed tough and waited for my moments. It was similar to my match on Saturday against Christian [Harrison]. I waited for the right balls and used my inside-out forehand really well at the end to keep him moving. All credit to him for playing a great match, but I’m really pleased with how I was mentally after getting broken those five straight games.

Heck of a finishing point too. [33-shot rally on match point]
Yeah, I was pretty tired and he dropped a couple balls short. I stepped in a little bit and managed to pull the trigger on the last one (a forehand winner down the line) and hit my spot where I wanted to hit it. I’ve been working countless hours with my coaches Devin and Facu on that ball. That is, to aim short a little bit. He calls it ‘the swirler’. That’s what happened on that last ball. It’s just a really great feeling to win the title this week and I don’t think I’ve ever felt like that.

On top of that, you’re into the Top 200 and the US Open qualifying. That has to be a load off your mind.
I’m so pumped for that. I got some messages from some coaches and one [Mark Hilton] said to me to not be satisfied yet. It’s just a great opportunity and I had everything to gain today. I’m really happy and looking forward to the US Open.

You’ve had the opportunity to train with Andy Murray. What have you learned from him?
I’ve watched Murray this summer and he’s an absolute beast. He doesn’t waste a point and doesn’t waste a ball. He’s 100 per cent all the time. I had one really good practice with him at Wimbledon, right before Eastbourne, and you can learn a lot from his professionalism and mentality to always get better.

And look at Jordan Thompson this week. He wasn’t playing his best tennis, but he’s just so mentally tough and he competes like an animal. That’s what my coach Facu said to me this week. Jordan is going to be mentally tough, but you need to be tougher than him. Thommo and Andy are two great role models.

It’s a quick turnaround going to Lexington, but how do you celebrate this?
My coach and I are going to New York City for the night and maybe go out to dinner. I fly from LaGuardia Airport to Lexington on Monday. It will be nice to spend the night there and take it easy.
In tennis, you have to back up great results so I’ll be all in, in Lexington. I’ll try to keep the momentum going.