Simona Halep fights off Coco Gauff, Beatriz Haddad Maia stuns Belinda Bencic in Canadian Open
Twice champion Halep secured a nervy 6-4 7-6(2) win on Friday and advance to the last four for a fifth time.
Romania's Simona Halep fought off a late rally from Coco Gauff and Brazil's Beatriz Haddad Maia pulled off another three-set upset as both made the semi-finals of the Canadian Open on Friday.
Twice champion Halep secured a nervy 6-4 7-6(2) win on Friday and advance to the last four for a fifth time.
The former world number one, up a set and leading 4-1 in the second, looked headed for an easy passage into the last four.
But Gauff dug in and rallied to force the second set to a tiebreak before 15th-seeded Halep finish off the 10th seed in the tiebreak to maintain her dominance over the American.
In four career meetings, including three this year, Gauff has yet to take a set off Halep, who next faces another American in seventh seed Jessica Pegula - a 6-3 6-3 winner over Kazakh Yulia Putintseva.
"I'm really pleased with the way I stayed there strong mentally," said Halep, after reaching her 29th career semi-final at a WTA 1000 event - more than any other player.
"And I fought for every point which was really important because she's doing the same thing. Mentally I'm strong even if I struggled a little bit in the second set."
Halep certainly struggled in the second as she twice served for the match at 5-4 and 6-5 only to be broken each time.
But the twice Grand Slam winner refocused in the tiebreak to stop the contest going to a third and registered her 36th win this season behind only Iga Swiatek (48) and Ons Jabeur (37).
The 30-year-old also had to wrestle with her serve, committing eight double faults while giving French Open finalist Gauff plenty of chances with 12 break opportunities.
Haddad Maia humbled 12th seed Belinda Bencic of Switzerland 2-6, 6-3, 6-3 to become the first Brazilian to reach the semi-finals of a WTA 1000 tournament.
The 26-year-old from Sao Paulo, who stunned Polish world number one Iga Swiatek in the previous round, needed two hours and 11 minutes to edge past 2015 champion Bencic.
She will meet former world number one Karolina Pliskova who prevailed 4-6 6-4 6-4 against Zheng Qinwen of China in the last quarter-final match.