LONDON -- China's Liang Wenbo won a marathon battle on Monday to qualify for the final stages of the Snooker World Championship in Sheffield.

In the fourth round qualifying match, Liang seesawed with Irishman Fergal O'Brien until 9-9 before he cleared the table with a break of 141 to win the deciding frame.

The 33-year-old Liang last played at the Crucible in 2017. His best result at the World Championship was a quarterfinal finish in 2008.

This year's World Snooker Championship will be staged at Sheffield's Crucible Theatre from July 31 to Aug 16. Reduced crowds will be permitted to attend every session, as the tournament is one of the pilot events ahead of the full, socially-distanced return of sporting events in England from Oct 1.

China's Ding Junhui and Yan Bingtao have already earned their places in the final thanks to their top 16 rankings, along with defending champion Judd Trump, veteran John Higgins and five-time world champion Ronnie O'Sullivan.