World number eight Stephen Maguire is out of the Australian Goldfields Open after losing 5-2 to former world champion Ken Doherty in the last 32.
In a low-scoring contest, world number 29 Doherty's 67 was the highest break of the match, but further runs of 64 and 61 helped him overcome the Scot.
John Higgins' conqueror Matthew Selt claimed another scalp as he beat seven-time world champion Stephen Hendry 5-1.
World number one Mark Williams beat Barry Pinches 5-2 to reach the last 16.
But another Welshman, Matthew Stevens, is out after a 5-4 loss to Liang Wenbo.
The Chinese player registered breaks of 71, 111, 51 and 120 and was on course for a maximum 147 in frame seven after potting 15 reds and 15 blacks, but ran out of position from the final black and missed the yellow.
Dubliner Doherty, 41, was delighted to notch up a win against a high-ranking opponent.
"I played pretty well and I'm delighted to have beaten such a tough opponent," he told World Snooker. "It's been such a long time since I've beaten someone of Stephen's standard, a top-eight player."
Selt, the world number 43 who came through two qualifying matches, continued his run by beating Hendry, who opted not to retire at the end of last season, in a scrappy encounter.
"After beating John [Higgins] I felt amazing but I was brought down to earth with that performance," said Selt, who will play Shaun Murphy in his first ever ranking quarter-final.
"I didn't feel like I did yesterday and Stephen didn't play well at all. I only had five hours sleep last night so that might not have helped, but if Stephen had played well he would've won."
Williams was unimpressed with his own form despite advancing to a last-16 meeting with David Gilbert. "The way I played was just awful, appalling, and I don't know why it was so bad," said the two-time world champion.
"I was unhappy with every part of it. It's about getting through but you don't want to play like that.
"We both dragged each other down; I was missing everything and he was missing everything. I have no chance in my next match if I play like that."
Mark Selby produced a superb comeback from 3-0 behind and 68-13 down in the fourth frame to beat Joe Perry 5-3.
"Joe was brilliant in the first three-and-a-half frames and I should've gone 4-0 down. If I had then I would have been out of the tournament," said Selby. "But I managed to grind myself back into it."
Stuart Bingham gained revenge for his World Championship defeat by Ding Junhui to win a high-quality encounter 5-2.
Bingham missed out on a place in the elite top 16 in the world after letting a 12-9 lead slip before losing 13-12 against Ding in Sheffield in April.
"It took me about five days to get over that defeat," said Bingham. "I said revenge will be sweet - and it tastes nice."