China's Ding Junhui was one frame from defeat as he trailed Judd Trump 12-4 in the quarterfinal clash at the snooker World Championship after the second session at Sheffield, Britain, on Tuesday.

Trump, aiming to reach the final for the first time since 2011, jumped ahead 6-2 in the first session and opened the second session with a century, and took the next two to go 9-2 ahead, before Ding pulled two back.

The 25-year-old then stroked in 127 and 116 on his way to taking the last three frames of the session for a comfortable lead.

They will meet in their third session on Wednesday morning and the winner will face Ronnie O'Sullivan or Stuart Bingham in the semifinals.