Coco Gauff was put to the test by Kayla Day in her first match at the Canadian Open but triumphed in straight sets to reach the third round.

Gauff, playing for the first time since losing a semi-final epic at Wimbledon to Karolina Muchova, dug deep to earn a 6-2 7-5 victory in one hour and 47 minutes.

The 22-year-old made a stunning start, racing into a 5-0 lead, though she also had to fend off three break points along the way.

Day pulled two games back, defending a set point to break Gauff's serve, but the two-time grand slam champion broke straight back to take the first set.

The pair were evenly matched at the start of the second, with Day fighting off three break points in the fourth game, before they traded four straight breaks – the 26-year-old stopped Gauff from converting her first match point in the process.

Day then clawed her way back to 5-5, but Gauff was set on not going to a decider and won the final two games to book her place in the next round.

Off to a good start @CocoGauff secures her first win in Toronto by defeating Day in straight sets.#NBO26 pic.twitter.com/MgaY7O2kK9

— wta (@WTA) August 5, 2026

Elsewhere, Mirra Andreeva stormed to a straight-sets victory over Karolina Pliskova in her first outing since the disappointment of her second-round exit at Wimbledon.

The Russian took just 55 minutes to brush past her opponent with a 6-0 6-2 victory.

Iva Jovic will also join them in the third round after her 6-3 7-5 victory over Magda Linette, and she will face Alina Korneeva, who bested Emma Navarro 6-2 6-2.

Gauff stays perfect in Canadian openers

This is Gauff's sixth appearance at the Canadian Open, and she is yet to lose her first match at the tournament (6-0), dropping only one set in that span (against Danielle Collins last season in Montreal).

Among Americans, only Serena Williams (148) has claimed more WTA-1000 main draw wins than Gauff (115) since the format's introduction in 2009.

Meanwhile, only Martina Hingis (154) has claimed more Tier I/WTA-1000 main draw wins than the 22-year-old (115) before turning 23 years old since the format's introduction in 1990. 

As for Andreeva, the Canadian Open was the only WTA-1000 event where she had yet to claim a main-draw victory, but she ensured that run did not continue with a stellar performance.