Tennis star Bianca Andreescu has won the 2019 Lou Marsh Trophy as Canada's athlete of the year.

Andreescu, 19, is the first tennis player to win the award. The native of Mississauga, Ont., became the first Canadian to win a Grand Slam singles title when she defeated American star Serena Williams in the final of the U.S. Open.

"Wow, I'm so thankful for this award. I was not expecting it and to be the first tennis player to win is even more surreal," said Andreescu. "None of my success this year would have been possible without the support from all of Canada."

The winner of the Toronto Star award is selected annually by a panel of sports journalists from across the country. Andreescu was a unanimous choice for this year's award.

WATCH | Bianca Andreescu named Canada's athlete of the year:

Canadian tennis star Bianca Andreescu became the first Canadian to win a Grand Slam singles title. 4:09

Her star-making performance at the U.S. Open capped a stellar year for the Thornhill, Ont., resident, who also won the Rogers Cup in Toronto and the prestigious BNP Paribas Open at Indian Wells, Calif.

She earned over $6.5 million US on the season and is ranked fifth in the world after starting the year ranked No. 152.

WATCH | Andreescu's sit-down with CBC Sports:

Bianca Andreescu is the 2019 recipient of the Lou Marsh Trophy as Canada's athlete of the year. 3:13

The iconic shot of Andreescu at the U.S. Open came when she collapsed to the court after match point against American legend Williams.

"I was thinking about all those tough times that I've been through. And just realizing how how much dedication and hard work I put into this sport, how all those times are worth it," Andreescu told CBC Sports on Monday.

"I just laid on the ground. I just let everything out and it was just an incredible moment. My parents were there, [my dog] Coco was there, my whole team. My best friend too. So, it was a really good moment for me."

Recent Lou Marsh Trophy winners

2019 — Bianca Andreescu , tennis

, tennis 2018 — Mikael Kingsbury , freestyle skiing

, freestyle skiing 2017 — Joey Votto , baseball

, baseball 2016 — Penny Oleksiak , swimming

, swimming 2015 — Carey Price , hockey

, hockey 2014 — Kaillie Humphries , bobsleigh

, bobsleigh 2013 — Jon Cornish , football

, football 2012 — Christine Sinclair , soccer

, soccer 2011 — Patrick Chan , figure skating

, figure skating 2010 — Joey Votto , baseball

, baseball 2009 — Sidney Crosby, hockey

Andreescu also credited her visualization tactics for keeping her calm in the ultimate pressure moment of the U.S. Open final against Williams. The Australian Open looms as the next major Andreescu is eyeing.

"I've just kept visualizing that because I really believe in manifestation. So, I guess now my next goal would be to visualize the Australian Open trophy and becoming number one in the world by the end of next year. I think it's definitely possible if I stay healthy," Andreescu told CBC Sports.

WATCH | Andreescu's rapid rise to stardom:

At the end of the 2018 calendar year, canadian tennis sensation Bianca Andreescu was ranked 152nd in the world. Now, she's ranked fourth. How in the world did she get here? 2:18

Andreescu's coach, Sylvain Bruneau, said recently that her performance at the season-opening ASB Classic in Auckland set the tone for the year. Andreescu beat former world No. 1s Caroline Wozniacki and Venus Williams before falling to Julia Georges in the final.

"I was like, 'OK she's ready now,"' Bruneau said. "I mean, not eventually, but now. She's now at the point where she's able to really come up big and take those big names down and make a name for herself and do something good.

"I knew it was going to happen and I guess Auckland was the moment where I thought, 'OK maybe we don't need to wait. Maybe it's now."'

Eyeing 2020 Olympics

Andreescu, who finished the season with a 48-7 singles record, is recovering from a knee injury she suffered during the WTA Finals in late October.

While it "isn't a really big issue" anymore, she will take some time off in preparation for her next tennis stint in Australia.

Andreescu also said she is gearing up for the 2020 Summer Olympics in Tokyo.

"I'm going to do my best to make it because I've been watching every Olympics ever since I was a little girl. Just the atmosphere I hear from so many athletes that've played [in] it. They say that it's the best moment, best environment, best everything that's ever happened to them," Andreescu told CBC Sports.

"So, if I make it, it will be a really cool experience, I'm sure."

"Canadian sports crushed it this year so there are definitely many other athletes who deserve a piece of this award as well — we all motivate each other to be better," said Andreescu. "I can't wait for what 2020 will bring and am always proud to represent Canada at the highest level."

The Lou Marsh Trophy has been awarded annually since 1936 with a three-year hiatus during the Second World War.