Jessica Pegula crushed Patricia Maria Tig 6-3 6-1 at the US Open on Thursday to set up an enticing third-round clash with Elina Svitolina.
The clean ball-striking of the top-ranked American was more than the world number 700 from Romania could handle in a match that lasted just over an hour.
Pegula, seeded third, never trailed in a contest where she won 80% of her first serve points and broke Tig's serve six times.
Next up for the Buffalo native is Ukrainian Svitolina, who came from behind to beat Anastasia Pavlyuchenkova of Russia earlier in the day.
Pegula edged Svitolina in a three-set battle in Washington D.C. earlier this month and holds a 3-1 advantage in their career meetings.
"Every single match we play is just a really good battle," Pegula said.
"I feel like we play to each other's games where we make each other play better and we always have really great matches."
Russian Daria Kasatkina battled back to defeat American Sofia Kenin 2-6 6-4 6-4 and reach the third round.
The 13th seed looked to be heading out of the tournament after Kenin cruised through the first set and took a 3-1 lead in the second.
But she settled in from there, breaking Kenin for 3-3 and again to level the contest at a set apiece.
Kenin, a former Grand Slam champion now ranked number 101 in the world, broke in the opening game of the decider but was broken right back in a match that featured 14 total breaks of serve.
Kasatkina and Kenin have now split their four career meetings.
British number one Katie Boulter came from a set down to secure a place in the third round.
The 27-year-old matched her run at Wimbledon this summer after a gutsy 5-7 6-1 6-4 victory over China's in-form Wang Yafan.
Wang was on an 11-match winning streak, including beating seventh seed Caroline Garcia in the first round, but she was outlasted by Boulter in the New York heat.
In a tight first set, Boulter retrieved an early break, was given a warning for angrily swatting the ball away and had three set points on the Wang serve.
But she was unable to convert any of them and Wang promptly broke to wrap up the set.
However Boulter, from Leicester, cleared her head impressively and dominated the second set to level the match.
Having broken again for 5-4 in the decider she suffered a horrible wobble, throwing in two double faults in the first three points.
But once again Boulter recovered her composure and wrapped up a fine win when Wang hit the net.
She said: "I am super happy with today – very, very proud of myself. I had to dig really deep.
"I had a few set points in the first set which I wasn't able to convert. She played some really good tennis and I had to really battle and go for it at the same time.
"Credit to her. She is a great player and doesn’t make it easy. I managed to get over the line so I am extremely happy."
Boulter will face 21-year-old American Peyton Stearns, the world number 59, in what looks a very favourable draw, for a place in the last 16.
