REDCAR'S Mike Dunn claimed the biggest win of his snooker career this afternoon as he stunned world number two Mark Selby to reach the China Open semi-finals.

The 42-year-old veteran, ranked a lowly 73rd in the world, beat Selby 5-3 in Beijing and will tackle home favourite Ding Junhui tomorrow for a place in the tournament's showpiece match.

Journeyman Dunn thought about quitting the professional tour last season, so despondent was he to be consistently losing in the first round at low-profile events or in qualifying tournaments week after week.

But victory over Selby and a first ranking event semi-final of his 23-year career provide the justification for taking another crack at the sport.

Before the match, Dunn had said that he would not be worried if Selby thrashed him 5-0, given he was delighted to have already come so far.

But now the North-Easterner, who is already guaranteed prize money of £21,000, can start dreaming about a major title.

Ding will start tomorrow's semi-final as a strong favourite, but the same was true of Selby today.

China's leading player, who beat Mark King 5-2 in his own quarter-final, is aiming to become the first player since Stephen Hendry to win five ranking titles in a season.

World number one Neil Robertson and Ali Carter will go head to head in the semi-final on the opposite side of the draw.