Britain's Johanna Konta produced a commanding display to beat Belinda Bencic 6-2 6-1 and secure her place in the US Open fourth round in New York.
Konta, showing no sign of the health issues that affected her during the second round, brushed aside the Swiss 24th seed in 52 minutes.
Konta served with pace and accuracy from the start to keep 19-year-old Bencic on the back foot and a run of seven unanswered games gave her complete control.
She did not give away a single break point, won 19 out of 20 points on her first serve and hit 29 winners to her opponent's nine.
"I feel overwhelmingly happy," said Konta, who faces Latvia's Anastasija Sevastova in the next round.
"I felt I did a good job playing the match at hand and I focused all my energies into this match. I was happy how I dealt with things."
Konta had collapsed on court in her previous match and needed almost 15 minutes of treatment before feeling able to continue.
"I'm still recovering in every way," she added. "I think it was quite a traumatic experience. I'm just still working on getting better."