Defending champion Kyren Wilson was ousted from the World Snooker Championship in Sheffield, England, by China's debutant Lei Peifan 10-9 in the first round on Saturday.

Thirty-three-year-old Wilson led 6-3 after the morning session in the opening match, but met strong challenges from Lei from the beginning of the evening session as the 21-year-old Chinese qualifier took six consecutive frames.

The world No. 2 fought back to force a 9-9 draw, but Lei remained calm to seal the victory by winning the deciding frame 80-14.

"It feels amazing. The Scottish Open was my first title and this was my Crucible debut. Both moments are very special to me," said Lei, who won his first ranking title at the Scottish Open last December.

Wilson admitted that the defeat was hard to take, but also acknowledged his achievements over a long season.

The 39th-ranked Lei will face the winner between China's Zhao Xintong and Jak Jones of Wales.