Northern Ireland's Joe Swail booked his place in the quarter-finals of the Royal London Watches Grand Prix with a scrappy 5-2 victory over Scottish qualifier Marcus Campbell.
Campbell, from Dumbarton, struggled to reproduce the form which had seen him win four out of his five round-robin group matches.
The Scot managed a high break of just 39 as Swail battled his way to a meeting with Ronnie O'Sullivan in the next round.
Former world champion Shaun Murphy proved too good for Welshman Ryan Day - thanks to breaks of 54, 68, 61 and 86.
Day, beaten 9-4 by Murphy in last season's Malta Cup final, had breaks of 82 and 100, but they were not enough to beat the 2005 Crucible king.
"It was a cracking match," said Murphy.
"He's a class act, so I'm pleased to be into the quarter-finals. I'm prepared to do whatever it takes to win."