Snooker: O'Sullivan in control while Ebdon and Fu drive the crowd potty

Ronnie O'Sullivan has yet to hit his awesome stride at this year's world championship but even a below-par Rocket is too good for most as the twice champion proved last night in building up a 5-3 overnight lead in his semi-final against Graeme Dott.

Dott cued serenely, scored heavily and held his own in the safety exchanges in the opening four frames but could still only share them, and then lost three on the bounce before a composed 70 break to take the last. O'Sullivan let him in with a miss when 44-2 ahead.

Dott made 121 with his first visit to the table of the night for 1-0. O'Sullivan edged the second with a 34. Dott, who won the first five frames the last time this pair met at the Crucible ­ in the 2004 final ­ hit a 68 for 2-1 but O'Sullivan won the next four for 5-2, with a 66 break in the fifth his top score of the evening.

The evening's action was in stark contrast to the first session of the other semi, between Peter Ebdon and Marco Fu. The BBC studio at the Crucible received an email from two snooker fans in Belgium shortly before 6pm. Anticipating a couple of hours watching Ebdon-Fu, they had opened a bottle of wine. By the time they sent the email, four hours after it started, the match was still in only the seventh frame, and the Belgians were on their third bottle.

As they polished it off, Ebdon took a 4-3 lead, and it's not hard to imagine them being well into bottle number four before Fu levelled at 4-4 to conclude their day at 6.48pm.

There may have been slower, patchier, edgier, cagier sessions in the world semi-finals, but if anyone could remember yesterday, they were probably too comatose to speak up and say when.

One punter in the crowd spoke up, at about 6.20pm. "Come on lads, get on with it," he shouted. "It's like watching paint dry!" The fan was given the verbal equivalent of a yellow card by the referee. Securing a yellow at the first attempt was a feat worthy of praise yesterday.

In defence of the protagonists, a world semi-final is about as high-stakes as it gets, not least for Fu, who has never been this far before and is only the second man from Asia to reach the last four. (On a digressive note, and it was an afternoon that needed them, Fu is from Hong Kong but spends much of his time in Llanelli, at the snooker club owned by his new mentor, Terry Griffiths, while Ebdon, as English as they come, lives in Asia, or Dubai to be precise). Ebdon took the second with a break of 56. Fu got the third with breaks of 32 and 25.

Ebdon, who has been playing superbly this fortnight, and with a dash of pace now and then to complement his steely concentration, hit 42 and 50 for 2-2, then went ahead with two breaks of 39 in the fifth. Their eighth and final frame lasted 47 minutes, with errors too numerous to count. Fu clawed back from 41 points in arrears to snatch victory on the colours. (Slowly, of course).