Elena Rybakina suffered a shock defeat to Alina Charaeva in her first match as the world number one on Saturday, crashing out of the China Open in the second round.

Armenia's Charaeva, who is ranked a lowly 118th by the WTA, fought back from a set down to triumph 3-6 6-4 6-3 and tee up a meeting with Great Britain's Sonay Kartal. 

Since the WTA Rankings were first published in 1975, Naomi Osaka was the only player to have lost her first match at the top of the charts, going down to Kristina Mladenovic at the Dubai Tennis Championships in 2019. 

But Rybakina matched that unwanted feat after a lacklustre serving display, only getting 57% of her first serves in and winning just 60% of points when she did, compared to Charaeva's respective figures of 64% and 76%.

Having got three of the five breaks of serve in a topsy-turvy opener, the Australian and US Open champion also inched ahead in game three of the second set, only to immediately be broken back.

Charaeva broke again in game 10 to force a decider, and her constant pressure throughout the third was rewarded in game six, with Rybakina unable to hit back thereafter. 

2 - Since 1975, Alina Charaeva is just the second player to defeat the World No. 1 in their opponent’s maiden match holding the WTA's top ranking, after Kristina Mladenovic (Dubai 2019). Upset!#ChinaOpen | @ChinaOpen @WTA pic.twitter.com/ygXb0VmVIJ

— OptaAce (@OptaAce) October 3, 2026

Earlier in the day, third seed Coco Gauff overcame a stern test against Colombia's Camila Osorio, eventually prevailing 7-6 (7-4) 4-6 6-2.

Gauff will face home favourite Sun Xinran in the third round, while Iga Swiatek will take on Donna Vekic after beating another Chinese player, Gao Xinyu, in straight sets.

Elina Svitolina beat Katerina Siniakova, while Belinda Bencic downed Anastasia Zakharova and Iva Jovic eliminated Harriet Dart. 

Rybakina's opening-round run over

Rybakina had not played competitively since her Flushing Meadows final success against Aryna Sabalenka, and there were clear signs of rust from the world's top player here.

She arrived in Beijing having won each of her last 14 opening-round matches at WTA 1000-level (last losing to Ashlyn Krueger in Miami last year), while she was chasing her 50th Tour-level win of 2026, having only previously brought up a half-century in 2025 (59).

However, Charaeva – whose round-one victory over Yuliia Starodubtseva was her first-ever at WTA 1000-level – produced a career-best display, becoming the first Armenian to beat a WTA number one.

It was the 24-year-old's second career win over a former grand slam champion, having also defeated Sofia Kenin in Seoul (in the round of 32) last month.