By Julian Shea BBC Sport at Wembley

Ronnie O'Sullivan 5-6 Ken Doherty

Doherty took control in the final frame

Ken Doherty sent Ronnie O'Sullivan crashing out of the B&H Masters with a superb deciding-frame break of 59.

The Irishman had squandered several leads during a see-saw match, but he found his groove at the end, benefiting from a lucky cannon to get among the balls.

"That 59 was the best of the season," Doherty said afterwards.

"I got everything going right, the atmosphere was great. Nights like this are what you play for."

Doherty joins Paul Hunter in the semi-finals of the Wembley tournament, with two quarter-finals to be played on Friday.

I'm disappointed but he made a brilliant 59 break in the last frame and deserved it for that Ronnie O'Sullivan

Overall, the standard of Thursday night's snooker was lower than might have been expected from two of the best players in the world.

Both men struggled to find their potting range in a contest that was dominated by scrappy exchanges and featured no century breaks.

"Both of us were a bit tight to start with and it took us a couple of frames to settle down," admitted Doherty.

"I've played here before shaking like a leaf but this time I felt great."

O'Sullivan remained upbeat despite the loss and paid tribute to his opponent's last-frame heroics.

"I'm disappointed but he made a brilliant 59 break in the last frame and deserved it for that," he said.

"One thing I learned was that I played the wrong safety shot in the last frame and that's something I'll take away and hopefully never do again."