Judd Trump could lose his world number one ranking before the end of the month after suffering a shock defeat by Thailand’s Noppon Saengkham in the first round of the China Open on Sunday.
Saengkham, ranked 45th in the world, claimed a 6-3 victory to set up a second-round meeting with either Ronnie O’Sullivan or Jackson Page.
Trump fought back from two frames down to level, before his opponent won three frames in a row to take control of the best-of-11 contest.
A match-high break of 120 put Saengkham 5-2 up, before the Thai won the final frame 78-0.
Trump, who won the China Open in 2011 and 2016, came into the event off the back of beating Kyren Wilson in the final of the invitational Shanghai Masters last week.
However, the 36-year-old has won just ranking tournaments in the past two years, the most recent of those the German Masters in February.
The China Open has returned to the World Snooker Tour calendar for the first time since 2019, and is now hosted in Taiyuan, 310 miles (500km) south west of Beijing, rather than the Chinese capital.
Trump has topped the world rankings since August 2024 but to have any chance of remaining at the summit he must win the Wuhan Open later this month and hope other results go his way.
Zhao Xintong is currently best placed to overtake Trump, with Neil Robertson and Wu Yize not far behind.
Trump was not the only seeded player to lose in the first round, as Barry Hawkins lost to Liu Hongyu, Mark Williams was defeated by Zhou Yuelong, and Ding Junhui was thrashed 6-1 by David Gilbert.
The winner of the tournament will receive prize money of £250,000, with the runner-up to bank £100,000.