Former champion Kei Nishikori’s Citi Open campaign is off to a flying start following a straight-sets win over familiar foe Sam Querrey on Monday. The Japanese World No. 67 clinched his seventh victory from 11 ATP Head2Head meetings against the American, 6-4, 6-4.

Nishikori arrived in Washington from Tokyo, where he had become the first man to reach three straight Olympics Games quarter-finals (l. to Djokovic). Despite the quick turnaround to adjust to conditions in the US capital, he broke three times and prevailed convincingly in 86 minutes .

“Yeah we have played a lot. It’s been many times,” the 2015 Citi Open champion said in his on-court interview. “It’s not easy playing Sam. He has a great serve and especially this surface he has more time to play but… I returned pretty good in those games and I’m very pleased how I played today.”

A former No. 4 in the FedEx ATP Rankings, Nishikori was rattling through his service games, as Querrey increasingly struggled to hold his own. No sooner had Nishikori fended off break points for the first time in the match at 2-3 in the second set than he turned the screws.

“That was toughest moment I think for today. If he had [won that] game I think he had the whole set,” Nishikori said. “I saved a couple of tough points… [I got a] little lucky but after that game I think I was a little more free and I was playing better.”

It was pivotal as he reeled off the last four games of the match to set a meeting with ninth seed Alexander Bublik for a place in the third round. The defeat consigned the 33-year-old Querrey to his fifth straight defeat, following his first-round win over Pablo Carreno Busta in the opening round at Wimbledon.

“I was really tired after coming from Japan and wasn’t sure if I was ready today but on the court I was fine, playing really good tennis,” Nishikori said. “First match is never easy, I wasn’t expecting 100 per cent but I hope I can keep going like this.”