Two double faults in the opening game. That is how Novak Djokovic's quarter-final against Alexander Zverev began on Sunday in Beijing, and for a set it looked as though the 39-year-old's body might finally be catching up with his ambition. Zverev, ten years younger and the tournament's top seed, broke immediately and never looked back in the first set, closing it out 6-4 while a sold-out crowd watched the age gap seem to matter. Then came the twist that defines this late chapter of Djokovic's career.

A flickering LED panel triggered a replayed point and a chorus of boos, Zverev's frustration visible, and somewhere in that chaos the Serb found his rhythm. He leveled the match with a cross-court winner that broke serve, then dug through a decider that stretched past two and a half hours, facing down 19 Zverev aces along the way before breaking at 5-4 to seal it, 4-6, 6-4, 6-4. It is Djokovic's 32nd consecutive win, a streak that now carries him into a semi-final against Daniil Medvedev, who beat Argentina's Francisco Cerúndolo 7-6, 6-3 to get there. Elsewhere in the draw, Hubert Hurkacz downed Karen Khachanov to reach the last four, where he meets Australia's Alex de Minaur, a 1-6, 6-2, 6-3 survivor against Andrey Rublev.

The women's draw delivered its own upheaval. Aryna Sabalenka, the world No. 2, was beaten 6-4, 6-3 by 20-year-old Nikola Bartunkova, ranked 34th, who fired four aces and refused to blink. Sabalenka wasted five break points in one torturous sixth game and later hurled her racket in frustration, leaving the China Open without either of its top two seeds.