World number one Mark Selby overcame an unconvincing start to move into the semi-finals of the UK Championship with a 6-1 win over Matt Selt.
Selby won a slow opener on the pink and led 3-1 at the break despite Selt having good chances in the next three.
The Englishman then knocked in three fifty-plus breaks to secure a semi-final meeting with Neil Robertson.
World number 81 David Grace won five frames on the trot to beat Martin Gould and faces Liang Wenbo in the last four.
Leeds-based Grace was outclassed early on, with world number 24 Gould hitting two tons and a 72 to earn a 5-1 lead.
But Grace, who cleans snooker tables to supplement his earnings, eked away at the lead and secured victory in a nerve-wracking 11th frame to become the lowest-ranked UK Championship semi-finalist since Alan McManus in 1990.
China's Wenbo and world number three Robertson both won their afternoon quarter-finals 6-5, beating Hong Kong's Marco Fu and Scotland's John Higgins respectively.
World number one Selby is "relishing" the prospect of playing Robertson. "Neil has been playing the best snooker of the tournament so far," he told BBC Sport.