Canadian teenager Victoria Mboko delivered the upset of the National Bank Open on Saturday, dismissing top seed and world No. 2 Coco Gauff 6-1, 6-4 in just 62 minutes to reach her first WTA 1000 quarter-final. The 18-year-old saved all four break points she faced and capitalised on 22 unforced errors from the reigning French Open champion. Mboko, ranked No. 85 after starting the season outside the top 300, is the last Canadian in either singles draw and will face the winner of Zhu Lin versus Jéssica Bouzas Maneiro next. Elsewhere in Montreal, No. 24 seed Marta Kostyuk fought past McCartney Kessler 5-7, 6-3, 6-3, while ninth-seeded Elena Rybakina edged Dayana Yastremska 5-7, 6-2, 7-5. Kostyuk and Rybakina will meet for a place in the semi-finals. In Toronto, 20-year-old American Alex Michelsen kept his breakout week alive by defeating compatriot Learner Tien 6-3, 6-3 to book a maiden ATP Masters 1000 quarter-final. Ranked No. 34, Michelsen had already knocked out third seed Lorenzo Musetti earlier in the tournament and will next meet Russia’s Karen Khachanov, who eliminated Casper Ruud. Youthful success also extended to the doubles draw: France’s Arthur Fils and American Ben Shelton advanced to the quarter-finals with a 6-4, 7-5 win over veterans Édouard Roger-Vasselin and Hugo Nys. The pair will face fourth seeds Kevin Krawietz and Tim Puetz in the next round.