Ireland's Ken Doherty is the second player to reach the semi-finals of the World Championships with a 13-8 victory over John Higgins today.
Doherty had squandered a 10-0 lead to allow the Scot to pull back to 10-6 before the Dubliner seized the initiative to book his place in the last four.
Earlier Mark Williams defeated Stephen Hendry 13-7 to become the second player, after Ray Reardon, to regain the number one ranking spot.
In the other quarter-finals Stephen Lee currently leads Marco Fu 9-5 while the defending champion Peter Ebdon and Paul Hunter are locked in at four frames all.
Ken Doherty (Irl) bt John Higgins (Sco) 13-8.
Frame scores(Doherty first): 62-9 85-16 107 (107 break)-0 66-65 66-1 83-44 71-58 100-7 64-9 112 (112 break)-9 0-117 (113 break) 24-78 12-74 52-64 57-67 57-62 31-69 68-56 75-7 8-94 71-1