Xu Si of China knocked out world No. 1 Judd Trump of England 6-4 at the World Snooker Tour (WST) International Championship in Nanjing, east China's Jiangsu Province, on Wednesday, continuing to progress at the tournament.

Xu built a 2-0 lead with two breaks of 76, but Trump gained the lead back soon by clinching three straight frames. They exchanged the next two frames before Xu kept the 29-time ranking event winner from scoring a single point in the final three frames as the Chinese finished with runs of 104, 69, 58 and 68.

"It was my mindset during the key moments that helped," Xu said after the victory. "In the last frame, I felt a bit of tension, but luckily things went well, and I didn't leave any easy shots. Finishing the match felt really good. Sometimes you reach a point where you're very nervous, and then suddenly you're not nervous anymore."

"I feel there's a much smaller gap now between myself and the top players. Recently, many Chinese players have been advancing to the latter stages of tournaments, which shows a significant improvement overall," he added.

Trump's superb run of making at least the quarterfinals of 15 consecutive tournaments, winning four of those and reaching two other finals since January came to an end against an opponent who is ranked 48 places lower than him.

On the same night, in a match between two home players, Ding Junhui beat Jiang Jun 6-3 with a top break of 109 to advance to his first ranking event quarterfinals of the season.

Wuhan Open champion Xiao Guodong saw off Jack Lisowski of England 6-3 to join the elite 16 for the first time in his career and become a seeded player for the UK Championship later in November.