Former world No 3 Wattana recorded his best result in recent years by knocking out the Grand Prix and Saga Insurance Masters champion to reach the quarter-finals at the Newport Centre in South Wales.

Higgins's defeat means the entire top eight on the world ranking list has been wiped out.

After sharing the first four frames, Wattana knocked in a 76 to take the lead. The Scot levelled with a 95, then went 4-3 ahead.

But two-times Thailand Masters champion Wattana made a 42 and 60 to square the tie, before edging a scrappy decider 52-8.

He next faces Barry Hawkins, who is also his opponent in the last qualifying round of the World Championship on March 14.

"It was tough playing John. He's been the most consistent player this season so it's a big win for me. I'm over the moon," said Wattana.

"I've been in England for 21 years and sometimes you lose the motivation and hunger. But I've been practising hard and hopefully my best form is coming back."

Higgins said: "No way was I thinking this was going to be an easy game. I'm disappointed but that's the way it goes sometimes. You get your highs and your lows. I really struggled badly. It was a bad game and I didn't play well at all."

World champion Shaun Murphy reached his first ranking event quarter-final of the season, defeating Jamie Cope 5-4.

Hawkins saw off Ryan Day 5-3 to leave Mark Williams as the only Welshman remaining. Beckenham left-hander Hawkins, the provisional world No 9, knocked in breaks of 96, 104 and 53.

Ken Doherty's hopes of back-to-back ranking event victories were dashed when he went down 5-3 to Anthony Hamilton.

Trailing 4-2, the Malta Cup champion battled back to reduce his arrears to 4-3 and had a string of chances to square a gruelling contest. But a missed green into a middle pocket cost him dear as Hamilton, who had not won a match since October before this event, grabbed his chance.

The world No 17 produced a wonderful shot to sink the pink with a double to a middle pocket, and then kept his cool to pocket a pressure black along the top cushion.

Doherty admitted: "I had my chances, but I played a crazy shot on the green when I had a chance to go 4-4 and it cost me.

"It was some pink Anthony potted and then a good black to win the match, but I should have never given him the chance. I could have won all of the first four frames, but that's where I probably lost the match.

"It was still there for the taking if I'd have got back to 4-4. He was starting to feel the pressure out there, you could sense it. It's an opportunity lost because the draw had really opened up."

Former British and China Open runner-up Hamilton said: "It was two great shots on the pink and black, but I thought they were the right shots to take. Ken gives you nothing, so it's a great win for me."

Larkhall's Graeme Dott booked a quarter-final berth after a comfortable 5-2 victory over Ulsterman Joe Swail.

John Dee

The Nation