Top seed John Isner started his Washington campaign on Wednesday with a dominant 6-3, 6-4 win over Aussie James Duckworth. The 31-year-old American spiked 14 aces and lost only three points on his first serve (35/38) to take the second-round contest in 63 minutes.

Isner also erased the only break point faced against Duckworth, a 24 year old ranked No. 205 in the Emirates ATP Rankings.

“Last year I did well, and I’m excited about this year,” Isner said. “A lot of times I can get tripped up on my first match, I’m glad I got through it.”

Isner, a three-time Citi Open finalist (2007, 2013, 2015), is looking to make it seven consecutive seasons with an ATP World Tour title. The 6’10” North Carolina native is making his ninth main draw appearance and is the top seed at the Citi Open for the first time. He has his sights set on claiming the title on his 10th attempt.

“It would be great. I’ve been very close here quite a few times, so to win here would be great,” Isner said. “This tournament is very special to me. I was virtually unranked and made the finals at this tournament in 2007, so I was very fortunate. I’ve been back every year since except for 2012. But it’s a tough tournament to win.”

Seven of Isner’s 10 career ATP World Tour titles have come in July or August. In the second round, he will face 15^th seed Marcos Baghdatis, a 6-2, 6-4 winner over Duckworth’s countryman, John Millman. The Cypriot claimed 80 per cent of first-serve points and saved all four break points faced.

Third-seeded Australian Bernard Tomic posted a 7-6(4), 6-3 victory over Donald Young, his first in three FedEx ATP Head2Head encounters with the American lefty. The 23 year old served for the opening set at 5-4 but could not close it out, eventually claiming the tie-break on his first set point, 7/4, before landing the break at 3-2 in the second. He closed the match out after one hour and 24 minutes to set up a third-round meeting with 13^th seed Ivo Karlovic.

Sixth seed Jack Sock saw off Lukas Lacko 7-6(1), 6-4 to advance to the third round. The American struck 10 aces on his way past the Slovak and will next take on unseeded Brit, Daniel Evans. Sock’s countryman, qualifier Ryan Harrison, continued his strong run, upsetting No. 10 seed Viktor Troicki 7-6(4), 6-4.

Doubles: Johnson/Sock Upset Top Seeds 

In doubles results, Steve Johnson and Jack Sock took down top seeds Marcelo Melo and Bruno Soares in the opening round. The American pair prevailed 5-7, 6-4, 10-7 over the Brazilians. 

No. 2 seeds Daniel Nestor and Edouard Roger-Vasselin narrowly held off the American wild-card pairing of Taylor Fritz and Reilly Opelka 4-6, 7-6(4), 10-8, while third seeds Florin Mergeaand Horia Tecau had a more routine 6-3, 6-3 victory over another American wild-card duo, Denis Kudlaand Frances Tiafoe. 

Fourth seeds Treat Huey and Max Mirnyi were not so fortunate, however, having to retire while trailing 1-6, 4-3 to Henri Kontinen and John Peers.

Third seed Jeremy Chardy was in dominant form on Wednesday at the Konzum Croatia Open Umag, needing just 43 minutes to advance to the quarter-finals over qualifier Nikola Cacic.

Chardy dropped just six points in the second set and only lost four points on serve during the match. Next up for him is Carlos Berlocq, who won his second-round via retirement over Jiri Vesely, 7-5, 3-0.

Fourth seed Fabio Fognini notched a 6-4, 6-1 win over Hamburg semi-finalist Renzo Olivo. The Italian saved five of the six break points he faced to set a quarter-final clash with Damir Dzumhur, who survived another three-set match in Umag by defeating Thomas Fabbiano, 4-6, 6-1, 6-2.

Doubles

The upset of the day went to Martin Klizan/David Marrero, who knocked out top seeds Colin Fleming/Mariusz Fyrstenberg, 6-4, 3-6, 10-7 to reach the quarter-finals. They next face Tomislav Draganja/Nino Serdarusic.

Fourth seeds Nikola Mektic/Antonio Sancic beat Teymuraz Gabashvili/Leander Paes 6-0, 6-2 in 46 minutes to reach the last eight, where they will challenge Carlos Berlocq/Pablo Cuevas. The Argentine/Uruguayan tandem defeated Lukas Dlouhy/Sergiy Stakhovsky 7-5, 6-4.

Gastao Elias/Fabricio Neis topped Pablo Carreno Busta/Guillermo Garcia-Lopez 6-1, 6-3. They next face second seeds Nicholas Monroe/Artem Sitak.

Thomas Fabbiano/Franko Skugor ousted third seeds Andrej Martin/Hans Podlipnik-Castillo 2-6, 6-4, 10-5 for a quarter-final against Aljaz Bedene/Damir Dzumhur, 6-4, 6-1 winners over Riccardo Ghedin/Alessandro Motti.