It was the nearest thing to an upset so far during a tournament in which the six seeds to have completed their opening matches have all won, unlike last year when several top-ranked players were beaten early on.

Although Wellingborough-based Ebdon never really looked in danger of making a surprise exit, he was pushed all the way by Wattana, whose fortunes have taken a nosedive in recent seasons.

When it mattered the 1996 runner-up, who has won two ranking events this season, found the form which carried him to victory in the Regal Scottish Open, the final event on the circuit before the Crucible.

Ebdon trailed 25-0 in frame 18 as the 31-year-old from Bangkok tried to level the match, but a superb contribution which included many fine pots put him beyond the reach of his opponent.

‘‘I was very proud of that break - it was a bit special,’’ said 30-year-old Ebdon, who can now have a rest until Saturday when he meets Stephen Lee or Nigel Bond for a place in the last eight.

‘‘James had played very well and put me under pressure so I had to find something. It was nice to be able to dig deep like that and come up with the

answers.

‘‘He’s not a former world number three for no reason and he will be disappointed to have lost, but he didn’t do much wrong.

‘‘However, I thought the match was spoiled by the amount of ‘kicks’ we had. I don’t know why that was, perhaps it was the atmospherics, but a lot of chalk seemed to collect on the cue ball.’’

Ken Doherty, the only other man to have won two ranking tournaments this season, made a solid start to lead world number 114 Nick Dyson 6-3 in the other match of the morning session.

The Dubliner, champion in 1997, made a break of 101 to go 4-0 up but Dyson, cheered on by a large following from Cheshire, gave himself hope for tonight’s conclusion by winning three of the four frames after the interval.