As soon as Bianca Andreescu heard that Serena Williams was retiring from their Rogers Cup final, she went to her opponent's bench, took a knee, and started consoling the veteran tennis player.

Lost in that moment of empathy was the fact that Andreescu had just become the first Canadian to win the tournament in 50 years.

"I started tearing up because she was tearing up. It's because I know how she feels," said Andreescu on Sunday. "Injuries really, really suck."

Andreescu, from Mississauga, Ont., was up 3-1 in the first set at Aviva Centre when Williams called for a medical timeout. Less than a minute later, the chair umpire announced that Williams was retiring from the match, handing Andreescu her second WTA Premier title of the season.

WATCH | Canadian teen sensation Bianca Andreescu wins her 1st Rogers Cup:

Bianca Andreescu and Serena Williams shared an emotional embrace after Williams was forced to retire from the Rogers Cup final due to injury. Andreescu is the first Canadian woman to win the Rogers Cup since Faye Urban in 1969. 2:14

"It's not the way I wanted to win, but a win is a win so I'm really happy," said Andreescu, who is the first Canadian to win the title since Faye Urban of Windsor, Ont., beat Vancouver's Vicki Berner in 1969. The tournament was still played on clay courts and called the Canadian Open when Urban won.

Williams was impressed with the 19-year-old Andreescu's class in that shared moment on the bench, calling her a "great sportswoman" and an "old soul."

"She's wiser than her, what is she? Nineteen years old?" said the 37-year-old Williams, who added that the brief encounter with Andreescu was the highlight of the tournament for her. "She definitely doesn't seem like a 19-year old in her words, on court and her game, her attitude, her actions."

Andreescu also won at Indian Wells in March, the beginning of a 17-match win streak, not counting when she has had to retire from matches due to injury herself. She holds victories over seven of the top 10 players in the world this season, including Williams.

The first Canadian <a href="https://twitter.com/rogerscup?ref_src=twsrc%5Etfw">@rogerscup</a> champion in 50 years - congratulations, <a href="https://twitter.com/Bandreescu_?ref_src=twsrc%5Etfw">@Bandreescu_</a>! Truly an inspiration to players across Canada. Today you showed tennis fans what sportsmanship is all about. —@JustinTrudeau

"I would say that the win in Indian Wells was — I mean, it was a hard-fought battle," said Andreescu, referring to her three-set win over No. 8 Angelique Kerber. "So I felt like it was a sweeter victory at the time.

"But (the Rogers Cup) is at home. I've dedicated so much hard work and sweat on that tennis court and in this gym, so this tournament is definitely ten times more special."

Lou Marsh favourite

Andreescu and golfer Brooke Henderson are early front runners for the Lou Marsh Trophy as Canada's athlete of the year and the Bobbie Rosenfeld Award, The Canadian Press's female athlete of the year honour.

Henderson has won two LPGA events this season and has set the all-time record for wins by a Canadian professional golfer. Andreescu has her two titles this season and her world ranking will rise from 27th to 14th on Monday. Her previous high was 22nd.

Andreescu's Rogers Cup win was so fresh that she hadn't even considered that she might earn all-around honours like the Marsh or Rosenfeld.

A 2nd-round comeback<br><br>A gruelling QF injury<br><br>A SF straight-sets win<br><br>A Final victory <br><br>Bianca Andreescu earns her Rogers Cup trophy<a href="https://t.co/8BkChzem0h">https://t.co/8BkChzem0h</a> <a href="https://t.co/OXtBm0Bu0Q">pic.twitter.com/OXtBm0Bu0Q</a> —@cbcsports

"That hasn't crossed my mind. But if I win that, then it would be awesome. I'm not complaining right now," said Andreescu. "I haven't really thought about anything other than this win. So anything outside of this is a bonus."

The Rogers Cup was Andreescu's first tournament after a right-shoulder injury sidelined her since the French Open in May.

Battle of attrition

Andreescu had been on the court more than any other player at this year's Rogers Cup at 10 hours 54 minutes heading into Sunday's final. All that playing took a toll on Andreescu, who needed a medical timeout in her quarterfinal win over world No. 3 Karolina Pliskova to have her groin taped. Both legs were wrapped and taped for her next two matches.

Sunday's final lasted only 16 minutes before Williams's medical timeout brought it to a premature end.

"It's not easy for Serena, for sure, to pull out, especially to pull out in a final," said Andreescu. "I know how she feels because I've done that many times in my short career. But sometimes you just have to listen to your body."

WATCH | Bianca Andreescu post-match press conference:

Bianca Andreescu addressed the media following her win over Serena Williams in the finals of the Rogers Cup in Toronto. 13:39

Williams said the injury is a recurring back spasm that doesn't affect her ability to walk but makes serves and overhand shots painful. She expected to go to Cincinnati for the next stop on the WTA Tour to test it out ahead of the U.S. Open.

"The most frustrating part is that I've had these awful spasms a lot in my career," said Williams. "And they're incredibly painful, but it goes away after, like, 24, 36, maybe 48 hours, and like clockwork.

"So I do different treatments. I take a day off. But obviously, I didn't have 24 hours or plus to take off (ahead of the Rogers Cup final)."

WATCH | Serena Williams post-match press conference:

Serena Williams spoke to the media after having to retire from the Rogers Cup final due to injury. 5:50

Williams's retirement was the last in a string of high-profile injuries at this year's Rogers Cup. Fourth-seeded Simona Halep withdrew from her quarterfinal matchup with Marie Bouzkova.

On the men's side in Montreal, Milos Raonic of Thornhill, Ont., retired after two sets against Montreal's Felix Auger-Aliassime in a much-anticipated all-Canadian matchup. Sixteenth-seeded Gael Monfils then withdrew before his semifinal against world No. 2 Rafael Nadal.

Later Sunday, Katerina Siniakova and Barbora Krejcikova beat Demi Schuurs and Anna-Lena Gronefeld 7-6, 6-0 for the women's doubles title.