Coco Gauff's Montreal title hopes fade after a straight-sets loss to 18-year-old Victoria Mboko

An absolute surprise at the Montreal Open after Coco Gauff's defeat to young Canadian Victoria Mboko. The world No. 2 was far from her usual level, and while she managed to reduce her double faults, she had a poor 43% first-serve percentage throughout the match and ended up losing 6-1, 6-4 to the 18-year-old star.

Mboko gets revenge for her second-round loss at the Rome Open—where Gauff came back from a set down—and secures the best victory of her career. It is her first win over a top-10 player and guarantees her a new career-high ranking of world No. 55. The Canadian reaches her first WTA 1000 quarterfinals.

Mboko's Stunning Start in the first set

Mboko started strong with an early break and then, with great poise, held her first service game to lead 2-0. The Canadian didn't seem intimidated to be on center court, especially with all the Canadian fans watching and hoping to see their only representative in the fourth round advance.

Gauff managed to win only a single service game, but it did little for her. Mboko saved a break point in the fourth game and took control of the match, securing two consecutive breaks and strong service games. The Canadian had a 62% first-serve percentage against Gauff's poor 50%, while the Canadian won 67% of her service points compared to the American's mere 41%. The set ended with a convincing 6-1 in favor of the Canadian after just 26 minutes.

Mboko shows poise to seal gritty win

Things leveled out in the second set, with neither player allowing long rallies, and neither managing to get more than one point on the return during the first part of the set. They reached 3-3 without any surprises, a point at which Mboko faced her first break points. The teenager managed to save four break points—with huge support from the crowd—and stayed in contention, holding her serve to go up 4-3.

In the final moments of the match, Mboko showed a better ability to handle the pressure, holding her serve to move ahead 5-4, and then getting her first break opportunity, which she used to close out the victory 6-1, 6-4. She advanced to her first WTA 1000 quarterfinals.

Mboko's upset reshuffles Montreal draw

Mboko, who received a wildcard to enter the main draw, has knocked out the top seed and reorganized the draw, especially after the early exits of players like Mirra Andreeva (4th) and Jessica Pegula (3rd). Mboko now awaits her opponent between Lin Zhu and Jessica Bouzas Maneiro, two players who have never reached a WTA 1000 quarterfinal.

Whoever wins that match on Sunday night will be guaranteed to be a first-time semifinalist, while in the top half of the draw, the only remaining seeds are Kazakhstan's Elena Rybakina (90th) and Ukraine's Marta Kostyuk (24th). They will face each other this Monday for a spot in the semifinals, and the winner will be a favorite for a potential final.

Mboko's Breakthrough: Canadian teen set to crack the top 60

Victoria Mboko is guaranteed a total of 214 points so far added to her ranking, which will allow her to advance 30 positions (from No. 85 to No. 55), putting her at a new career-high ranking. She is one of only four players under 19 years old in the top 100, trailing only Mirra Andreeva (No. 5).

Should she secure another victory in the next round, Mboko could advance another 9 positions to No. 46, officially entering the top 50, which seems to be only a matter of time considering the high level she has shown this past week and the fact that she has virtually no points to defend for the rest of the season.