Daniil Medvedev continued his strong start to his US Open title defence after a routine second-round win over France's Arthur Rinderknech 6-2, 7-5, 6-3 in the Arthur Ashe Stadium on Wednesday.
After an inconsistent run-up to Flushing Meadows, Medvedev gained momentum after his straight-sets win over Stefan Kozlov in the first round on Monday and picked up where he left off against Rinderknech.
"In general, I'm happy with my level in the third set," Medvedev, 26, told reporters. "At the end of the match it was getting better and better.
"At the same time, a win is the most important. Try to get out as early as possible even if it is pretty late. Looking forward to the next round."
Medvedev frustrated Rinderknech with his flawless shot placement and pounced on the Frenchman's serve to keep him pinned back on the baseline, while also saving all three break points he faced as he controlled the contest from the start.
The Russian capitalised on several unforced errors from Rinderknech to easily clinch the opening set and although he faced greater resistance from the world number 58 in the second, he was able to break through and prevent a tiebreak.
Medvedev dictated play with penetrating groundstrokes and got the crucial break in the third set by claiming the fifth game, before racing to victory in two hours and 11 minutes as the clock ticked past midnight in New York.
"It's not so easy to play when you start at 10pm," said Medvedev, whose match began after Serena Williams beat Anett Kontaveit in three sets. "I had some experience, so I was ready. I tried to find a way to play my best tennis. That's for sure what happened in the first set."
"Arthur was a little bit slow, made some double faults and some unforced errors. Then I managed to keep the momentum going."
Medvedev, who won his maiden Grand Slam title a year ago, has now won 20 of his last 22 matches at the year's final major. He is bidding to become the first men's player to clinch consecutive US Open crowns since Swiss great Roger Federer swept the tournament each year between 2004 and 2008.
Awaiting Medvedev in the third round will be Wu Yibing, who became the first Chinese man to reach the third round at Flushing Meadows after beating fellow qualifier Nuno Borges of Portugal 6-7, 7-6, 4-6, 6-4, 6-4.
"He seems to play great," Medvedev said of Wu. "I'm expecting a tough match and will need to be at my best."
Nick Kyrgios joined Medvedev in the third round after powering past Benjamin Bonzi with a hard fought 7-6, 6-4, 4-6, 6-4 win over the Frenchman.
The big-serving Kyrgios struck 30 aces and won the final nine points of the match to end the punishing affair under the lights at Louis Armstrong Stadium.
"His level today was incredible, I was not expecting an absolute war," Kyrgios said in an on-court interview. "That could have gone either way. He was up a break early in the fourth but I played some really risky tennis late in the fourth set to win. I'm just happy to get through."
In their first career meeting, Kyrgios unleashed some spectacular shotmaking in the tiebreak and rode an early break in the second set to take a 2-0 lead.
Bonzi responded by taking the third set and a decider appeared all but inevitable when Kyrgios trailed Love-40 while serving at 4-4 in the fourth.
"My mentality was I'm probably going to get broken. I was almost gearing myself up for a fifth set," Kyrgios told reporters. "In those moments I just played really low percentage. I just kind of hit a dropshot here, hit the forehand cross-court, faked him out with the underarm... it got me out of jail."
After serving his way out of trouble he sealed the match by breaking serve for a fourth time when Bonzi, who made some acrobatic dives for balls during the match, was unable to will his shot over the net on match point.
The win sets up a third-round meeting with American JJ Wolf, who battled past Alejandro Tabilo 4-6, 7-5, 6-4, 6-3 earlier in the day, and keeps alive the potential for a showdown with Medvedev in the fourth round.