British number one Johanna Konta fought back from a set down to defeat third seed Elina Svitolina and reach the Canadian Open third round.
Svitolina looked in control when she took the first set in just 38 minutes.
But Konta showed remarkable resilience, winning eight out of nine games to take the second set and go a double break up in the decider on her way to a 3-6 6-3 6-2 win over the Ukrainian.
She faces American Coco Gauff in the last 16.
Victory was Konta’s first over Svitolina, the world number five and Olympic bronze medallist.
The result and performance was all the more remarkable given Konta was playing in her first tournament since the Nottingham Open in early June.
She withdrew from Wimbledon later that month when a member of her coaching team tested positive for Covid-19, then pulled out of the Tokyo Olympics after contracting the virus herself.
“That was definitely not an easy match. I’ve never beaten her in my career, so for me personally, this was a massive win,” Konta said to WTAtennis.com.
“She’s probably the toughest player for me on tour, so I’m quite pleased with myself.”
Konta, 30, is also looking for a first win over Gauff, 17, having lost to the teenager in last year’s French Open.
Gauff was on court for just 22 minutes after Russia’s Anastasia Potapova retired with an injury at 5-0 down.
Top seed Aryna Sabalenka survived a tough opening round against the USA’s Sloane Stephens, coming back from 4-1 down in the deciding set.
“It was a tough match and she played so well. She pushed me like crazy in this match and I don’t know actually how I won this won this one,” Belarusian Sabalenka said on court after the match.
“I was already in the locker room thinking what was going to happen next – doubles here, planning for the next weeks. I don’t know if that’s why I cooled down, and I was just playing and didn’t think about anything else.”
She will face Canadian wildcard Rebecca Marino, who reached a career high of world number 38 in 2011 before quitting the tour two years later, having struggled with depression for six years.
“I can’t sell myself short, I need to step up and do my best. If I play my game I stand a chance with all of these girls,” Marino said.
Two-time champion Simona Halep’s return to the WTA tour after injury ended in defeat against American Danielle Collins, currently on a 12-match winning streak.
Halep was playing for the first time since retiring in Rome with a calf injury that forced her to withdraw from the French Open, and prevented her from defending her Wimbledon title.
“It was a great match especially after a few months of break, I played really well and I’m happy with everything,” Romania’s Halep said.
“After three months, it’s tough to play three hours at a high level with someone who has been winning a lot of matches.”