The two-time world champion from Wales trailed three times to the Devon cueman, but the Englishman was unable to get over the line.

A break of 47 saw Hicks nick a scrappy first frame, but a knock of 64 was enough to get Williams back level. Hicks edged ahead again but once more Williams restored parity despite not looking on top form.

A 53 break put Hicks 3-2 up but Williams scraped back level and then a solid deciding frame saw him sneak into round two, where he will face Ronnie O'Sullivan or Marco Fu.

Chances

It was a more straightforward afternoon's work for Stephen Lee, who overcame fellow Englishman Michael Holt 4-1 on Tuesday.

Lee won the first frame but paid for a number of missed chances in frame two as Holt drew level.

The match swung in Lee's favour in frame three when, needing the final three colours to pinch the frame, he could manage only blue and pink, leaving his opponent to sweep up.

The 37-year-old from Wiltshire soon eased into a 3-1 lead and then finished things off with a 53 break, having trailed 52-17.

Stephen Hendry enjoyed one of his best results in recent years as he romped past Neil Robertson 4-1, winning the final three frames after Robertson had claimed his sole frame victory with a break of 135.

"I haven't had much success against the top players in the last few years," said Hendry, who has dropped out of the world's top 16. "I just played well, and when you do that you can compete. If you don't you've got no chance.

"In the last frame I expected to get the jitters, but I felt really comfortable clearing up, and that pleased me more than anything."

Stuart Bingham then eased past Mark King 4-2.

Scare

In the evening session, world number one Mark Selby suffered a huge scare before edging past Sam Baird 4-3.

Selby was one ball away from exiting the tournament but the 82-ranked Baird missed a simple blue to take the sixth frame and the match.

The 'Jester from Leicester' duly levelled and looked to be on his way to victory in the decider when he broke down with 28 on the board.

But Baird was unable capitalise, missing an easy red when amongst the balls to give Selby the chance to move 51 points ahead with 51 on the table.

Baird still had the chance to force a re-rack, but a miscue spelled the end as a below-par Selby booked his place in the second round.

Martin Gould awaits there after he overcame Peter Ebdon 4-2.