Bianca Andreescu gives most Canadian apology to crowd for winning US Open

In her Grand Slam debut, Bianca Andreescu defeated American tennis legend Serena Williams in straight sets to win Canada's first U.S. Open title in front of a hostile crowd openly rooting against her.

New York fans unmistakably rooting for American Serena Williams

Canada's Bianca Andreescu reacts to winning the US Open over tennis great Serena Williams in her Grand Slam debut. (Getty Images)

If you didn't know Bianca Andreescu was Canadian when she won the U.S. Open, you certainly realized it very quickly during her post-match interview.

"I know you guys wanted Serena to win, so I'm so sorry," Andreescu said to the crowd at New York's Arthur Ashe Stadium.

That crowd was decidedly against Andreescu throughout the women's singles final, cheering loudly for American favourite Serena Williams, who was searching for her record-tying 24th-Grand Slam title and seventh U.S. Open crown.

Andreescu said it was those cheers that were the hardest thing to overcome in a tight second set that saw the 19-year-old from Mississauga, Ont. let a 5-1 lead slip away, allowing Williams to claw back to 5-5.

But Andreescu kept her cool and won the next two games, becoming Canada's first ever Grand Slam champion in straight sets 6-3, 7-5.

And at that point, the crowd no longer mattered. Andreescu was on top of the tennis world. Her win will skyrocket her to a career-high No. 5 when the new WTA rankings are released on Monday.

And back home, Canada could not be prouder of this homegrown tennis superstar.