Mark Williams blasted the decision by snooker chiefs to scrap the maximum break prize and predicted it would stop players attempting a 147 at the Crucible.

Welshman Williams waltzed through to the quarter-finals of the World Championship with a 13-4 demolition of Stoke's Jamie Cope, becoming the first man to reach the last eight.

He made two century breaks, 106 and 109 in consecutive frames during this morning's middle session, but not at any stage did he think about going for the feat of 15 reds and blacks, followed by the six colours, snooker's ultimate individual feat.

The Welshman made a maximum in Sheffield six years ago, in a match against Robert Milkins, and in recent seasons there has been a £147,000 prize fund on offer for the feat, which has only been achieved nine times in the history of the tournament.

But that was scrapped this year in a cost-saving move, to the astonishment of former champion Williams who fears audiences may suffer from missing out on a magical moment.

‘I think it's terrible that there's not a 147 prize in this tournament,’ Williams said.

‘Even if it was £20,000 for a maximum break, it's got to be something for this tournament.

‘It's just a shame because apart from Ronnie O'Sullivan who still seems to be going for it as if it is £147,000, a lot of other players aren't even going to attempt it.

‘And that's what people come to see, big breaks and the possible chance of a 147. And there's just not one. Surely they can knock £20,000 off the top prize fund and give it for a max.

‘I'd never even think about going for one.’

Williams awaits the winner of the last-16 match between Mark Allen and Barry Hawkins.

Hawkins carries a 5-3 lead into Saturday, when the left-handed pair play morning and evening sessions to determine who goes forward to tackle the champion of 2000 and 2003.

A sloppy performance by Cope allowed Williams to win emphatically despite not playing as well as he can.

Williams said: ‘Although I played okay, he helped me along the way nicely, and I punished him for his mistakes.

‘You have to go to another level if you want to go further in this tournament. I know I've got the gears there, it's just a matter of moving up at the right time.

‘I don't mind who I play next.’

Williams, 36, is the provisional world number one for the start of next season, yet his recent Crucible record has been disappointing, and the quarter-final will be his first for five years in Sheffield.

‘In two of those years I've ended up playing Ronnie in the second round which is not easy,’ he said.

‘This tournament doesn't really start until the second week and I haven't been this far for so long I don't know what it feels like.

‘It's nice now coming to the second week still being in and I've got as good a chance as anyone else.’

Cope beat Welsh debutant Andrew Pagett in the first round but was 7-1 down after the first session against Williams and never threatened to recover.

‘It was over really after the first session,’ Cope said. ‘I didn't play very well in that.

‘I'm not far away from playing well which is the frustrating thing.’

Judd Trump marched towards a quarter-final place as he sped into an 11-5 lead, two away from victory, against Martin Gould.

Trump, the 21-year-old from Bristol who knocked out defending champion Neil Robertson last Saturday, believes he can claim the world title this year.

He offered more compelling evidence to support that confident view as Gould suffered in their second session.

If there is any consolation for 29-year-old Gould, it comes in the knowledge that an 11-5 lead is not necessarily a winning lead.

Gould led Robertson by that margin at the last-16 stage last year, but the Australian fought back to win 13-12.

The former casino worker from Pinner in north-west London can only hope that Trump falters in the manner of his own implosion last year.

Trump had a break of 108 in the second frame of the afternoon, but Gould managed to cut his lead to 6-5 with runs of 76 and 72, only for the two-frame gap to be restored with 69 from the man who knocked out Robertson in the first round this year.

‘If in doubt hit it as hard as you can?!!’ was Trump's message at the interval, as he turned to Twitter.

He had smashed the white off the table at the end of the fourth frame, and continued to be the aggressor when they returned, winning all four remaining with runs of 51 - twice - 84 and 67.

Ali Carter or last year's runner-up Graeme Dott will await the winner.

Dott and Carter's opening session was on the slow side, but the pace did not worry Dott who had trailed 3-1 early on but took four frames in a row to develop a 5-3 lead.

It was a different story between Dott and Carter tonight though, with a higher tempo and Carter fighting back well.

They shared the opening two frames, and then Carter went on a run of four in a row to lead 8-6, with breaks of 63, 86, 112 and 115.

Dott made it 8-7 though and the Scot finished the session with a run of 66 to level up at 8-8 ahead of Saturday afternoon's conclusion to the match.