US Open finalist Leylah Fernandez won a baseline battle against American 27th seed Amanda Anisimova 6-3 4-6 6-3 to book her spot in the quarter-finals of the French Open for the first time.

The only other time the Canadian left-hander made the second week of a Grand Slam was during her run to the final at Flushing Meadows in 2021 when she lost to fellow teenager Emma Raducanu.

"Today was a very complicated game and I'm happy I managed to get through," she said in an on-court interview, speaking in French.

"I knew she would fire a lot of winners and that I had to accept that and not get frustrated. I was so eager to get to play here. I'm happy all the hard work we've done, me, my father, paid off."

On an overcast and chilly morning on Court Philippe Chatrier, the 19-year-old Fernandez put pressure on Anisimova's serve from the outset and quickly racked up a 4-0 lead, mixing deft drop shots with crushing forehands.

The 20-year-old Anisimova, known for her easy power behind her groundstrokes, managed to get two service breaks back to make it 3-5 but could not stop Fernandez from taking the opener.

Three years ago, Anisimova, seeded 27th seed this year, became the youngest American to reach the Roland Garros semi-finals since Jennifer Capriati in 1990.

After a quick bathroom break, Anisimova returned more focused, found a bit more control with her powerful groundstrokes and advanced to the net more often to break her opponent's delivery twice to win the second set.

Anisimova had two breakpoint opportunities on Fernandez's first service game in the deciding set but the Canadian served an ace and then hit three crushing winners to hold.

Fernandez got the crucial break in the fifth game to nose ahead in the riveting contest as the American made her frustration evident by throwing her racket away after sending a forehand long.

The Canadian broke again in the ninth, converting her second matchpoint when Anisimova's return did not make it past the net.

Fernandez will play Italian world number 59 Martina Trevisan, who beat 47th-ranked Aliaksandra Sasnovich of Belarus 7-6(10) 7-5, for a place in the semi-finals.