John Isner made quick work of Australia's Bernard Tomic to advance to the quarter-finals of the New York Open on Thursday with a 7-6(7), 6-4 victory.
The big-serving American sent down 27 aces, won 85 percent points on his first serve and did not face a single break point as he wrapped up the match in 74 minutes at the Nassau Veterans Memorial Coliseum.
"I definitely served very well. I was down a set point in the first set and I came up with three aces," Isner said after the match.
He added, "I'm happy to be in the quarter-finals. Last year I lost my first match here, hopefully I continue to improve."
Isner, who was knocked out in the first round of last month's Australian Open, is the tournament's top seed after South African Kevin Anderson withdrew with an elbow injury.
Both players held firm on serve in the first set to force a tiebreak, which the 33-year-old Isner held his nerve to win.
Tomic fought till the end, striking 13 aces and saving five of the six break points he faced, as well as six match points in the second set, before Isner eventually claimed his first victory of 2019.
In the quarter-finals, the American will face Australian seventh seed Jordan Thompson, who defeated Christopher Eubanks 4-6, 6-1, 6-4 earlier.