By the numbers: Halep stays perfect vs. Gauff to reach Toronto semifinals

With a 6-4, 7-6(2) victory over Coco Gauff, Simona Halep secured another semifinal berth at the National Bank Open presented by Rogers.

The two-time former champion is through to the last four in Canada for the fifth time in her career. Here's a snapshot of 15th-seeded Halep's victory over No.11 seed Gauff, by the numbers:

4: Halep improved her head-to-head record against Gauff to 4-0 with the 1 hour, 47-minute victory. Their first meeting came at Gauff's breakthrough Wimbledon tournament in 2019, but their other three matches have been played this year. Halep was also victorious in Indian Wells and Madrid.

Halep has noticed the improvement in the American teenager in that time. 

"She's a bit stronger. She hits stronger. And the serve was much stronger today. Backhand is always hard," she said after the match. "I think she improved a lot since we played last time. It's always tough to play against her. She's fighting until the end. She doesn't give you a point, so you have to stay there and to fight."

8: Halep has, nonetheless, not lost a set against Gauff in their four meetings. Friday's second-set tiebreak marked the first time Gauff won more than four games in a set.

6: Halep broke Gauff's serve six times in victory. From 6-4, 4-1 up, the match got complicated: Halep failed to serve out victory twice, at 5-4 and 6-5, before ultimately winning the tiebreak. 

36: The win is Halep's 36th this season. That figure ranks third behind only Iga Swiatek (48) and Ons Jabeur (37).

29: Halep is through to to her 29th career semifinal at a WTA 1000 event. That is the most all-time. ahead of Serena Williams (26), Agneiszka Radwanska (23), Victoria Azarenka (22) and Maria Sharapova (22). She's now 29-9 all-time in quarterfinals at WTA 1000 events. 

51: Halep now owns a 51-23 career record against players from United States, with her record in 2022 standing at 6-1.

2: Halep is a two-time champion in Canada. She's won the title twice in Montreal (2016 and 2018) and was runner-up in Toronto to Belinda Bencic in 2015. 

0: Halep and her semifinal opponent, Jessica Pegula, have never played before. Pegula booked her spot in the semifinals for the second straight year with a 6-3, 6-3 win over Yulia Putintseva.

5: Pegula needed five match points to close out her 81-minute victory. She and Putintseva had never played previously.

20: Pegula hit 20 winners in victory, more than Putintseva's 12. She also broke serve three times. 

22: The top-ranked American now boasts 22 wins at WTA 1000 events in the last two years. She and Iga Swiatek are now tied for the Hologic WTA Tour lead in that statistic. 

4: Pegula is through to her fourth career semifinal at a WTA 1000 event. Earlier this year, she was runner-up to Ons Jabeur in Madrid.