Serena Williams withstood the determined challenge of Czech qualifier Marie Bouzkova Saturday, rallying for a 1-6, 6-3, 6-3 victory to reach the WTA Toronto final.

Williams, seeded eighth in a tournament she has won three times, will take on home hope Bianca Andreescu in the championship match on Sunday.

Williams will be seeking her first title since she won her 23rd Grand Slam title at the 2017 Australian Open — and her first since the birth of her daughter Olympia on September 1 of that year.

Meanwhile 19-year-old Andreescu will be trying to become the first Canadian in 50 years to lift the trophy.

Bouzkova, 21 and ranked 91st in the world, had said it was a dream come true to take on 37-year-old US superstar Williams, and she made a dream start —breaking Williams three times to take the first set in less than half an hour.

But Williams rallied, slashing her unforced errors in a second set that saw her win the last four games to force the decider.

“I just needed to be more consistent and not make so many errors and just mentally be ready to hit a thousand balls if I needed to,” Williams said. “In the first set, I was going for a little too much, so I just had to just play a different game.”

Bouzkova departs Toronto having beaten three straight Grand Slam winners in Sloane Stephens, Jelena Ostapenko and, in the quarter-finals, reigning Wimbledon champion Simona Halep — who retired injured after dropping the first to Bouzkova on Friday night.

Andreescu shot to prominence with a victory at Indian Wells in March, but this week marks her first tournament since she was forced out of the French Open with a shoulder injury.