Aryna Sabalenka suffered a shock 6-4, 6-3 defeat to Nikola Bartunkova at the China Open on Sunday. The second-seeded star struggled to find her rhythm against the 20-year-old Czech. "I focused on myself, to be calm," Bartunkova said after the win. Sabalenka has not won a title since March.

Aryna Sabalenka suffered yet another setback in a difficult second half of 2026, crashing out of the China Open after a shock 6-4, 6-3 defeat to world No. 34 Nikola Bartunkova in Beijing on Sunday.

The second-seeded Sabalenka struggled to find her best tennis against the 20-year-old Czech, who stayed composed throughout the one-hour, 35-minute contest to secure the biggest win of her career. Bartunkova also hit four aces as she stunned the four-time Grand Slam champion.

Sabalenka's problems began immediately as she was broken in the opening game. The Belarusian had chances to hit back, earning five break points in the sixth game of the opening set, but could not convert any of them. Bartunkova held her nerve, continued to defend impressively and eventually secured another break to take the first set 6-4.

The second set followed a similar pattern. Bartunkova remained calm while Sabalenka struggled to impose her powerful game. The Czech earned the crucial break in the fourth game and protected her advantage to move 4-2 ahead. Sabalenka's frustration boiled over as she threw her racquet after dropping serve. Bartunkova did not blink, serving out the match on her first match point when Sabalenka sent a return into the net.

"I focused on myself, to be calm. Aryna is great. She's a legend. She's a Grand Slam champion," Bartunkova, 20, said after the biggest victory of her career.

SABALENKA'S TROUBLES DEEPEN

The defeat adds another disappointing chapter to what has become a frustrating 2026 for Sabalenka. She began the year in sensational fashion, winning Brisbane before completing the Sunshine Double with titles at Indian Wells and Miami in March. She became only the fifth woman to achieve the feat.

But Sabalenka has not won another title since Miami. She reached the Australian Open final but lost to Elena Rybakina and later suffered another major disappointment at the US Open, where Rybakina beat her 6-4, 5-7, 6-2 in the final. That result meant Sabalenka would finish 2026 without a Grand Slam title for the first time since 2022.

Rybakina also replaced Sabalenka at No. 1 after the US Open, ending the Belarusian's long stay at the summit. Now, with Sabalenka out of Beijing in the third round, her season has taken another unexpected turn.