Peter Ebdon and Graeme Dott took their gruelling Betfair World Championship first-round first-to-10 match into extra time today.

The former world champions, who clashed in a Crucible final that finished at 12.52am seven years ago, will return for an additional session after tonight's scheduled matches to complete their tussle, with Dott 8-6 ahead.

The Scot led 6-2 following yesterday's opening session, which was truncated when the players had to be called off to allow the afternoon games to start on time.

With ground to make up today, they were even more tediously slow and managed a paltry six frames before being hauled off.

Dott was in trouble and appeared to be in a state of torment when Ebdon reeled in the lead by winning the opening four frames in a grindingly slow fashion.

But Dott's spirits were lifted when he scrambled through the next two, making him favourite in a match that could resume very late this evening. Another post-midnight finish was not out of the question.

Englishman Ebdon, who won the world title in 2002 but lost the marathon 2006 final, is a master of snooker psychology and was able to cling to Dott this morning despite having a highest break of just 45.

His tactical play was always going to be important with that low level of scoring, and it tied Dott in knots at times.

Whether Dott had slept poorly, or was being mentally exhausted by Ebdon's slow going, it was hard to tell, but he looked tired and was at times seen muttering to himself in his seat as his lead was whittled away.

Ebdon took one particularly long toilet break, that left Dott to stew and tested the patience of referee Terry Camilleri.

The highest break of the session came in its final frame as Dott fired in an opening 50 before fending off another threatened Ebdon revival, to establish what in the end was a diminished but welcome two-frame cushion.

On the other table, Northern Ireland's Mark Allen was struggling against Braintree-based Mark King.

Antrim potter Allen reached the semi-finals four years ago and won the Haikou World Open last month, but he fell 5-4 behind against qualifier King in another match that will conclude this evening.

Allen had the highest break of the session, an early 83, but 50 from King in the ninth frame gave the 39-year-old the edge.