Northern Ireland Open: Ronnie O'Sullivan beats Ding Junhui and Judd Trump sees off Scott Donaldson

In a high-quality match, neither player took a backward step, but O'Sullivan produced some of his best snooker since becoming world champion for a sixth time at the Crucible back in the summer.

The evening had promised to play out somewhat differently when Ding quickly found his stride, looking in ominous touch as he put together breaks of 121 and 87 to leave O'Sullivan stewing in his chair following a couple of early missed pots.

However, after Ding failed to pull off a tricky plant, O'Sullivan finally got a foothold in the match with a typically brisk hand of 58 which he followed with a run of 59 in a fourth frame where Ding was left to rue a couple of unforced errors of his own.

With the tide having now turned, O'Sullivan returned from the break looking much more assured and another frame-winning contribution (70) saw him lead for the first time as Ding watched on with concern.

The Chinese did have chances to get back into the contest in frame six but it was one that O'Sullivan ultimately bossed to put himself within sight of the winning line before wrapping up proceedings with a typically brisk run of 79, his fourth 50+ break of the match and one that sets up a Saturday afternoon semi-final with old foe Ali Carter.

“He came out flying,” O’Sullivan told Eurosport afterwards. “I was embarrassed at times, my positioning was amateurish compared to his.

“But I dragged him down to my level. I had to dig in deep. But I’m enjoying it.”

Over on the second table, David Grace produced a similarly impressive display as his dream run continued with a 5-2 victory over Yan Bingtao.

Grace, a former UK Championship semi-finalist, fell off the tour a couple of years ago, but has enjoyed a fine week that began with a handsome win over David Gilbert before he came from behind to see off the likes of Sam Craigie and Michael Holt.

Despite once again starting as second favourite, Grace was never behind in this last-eight encounter after clinching the opening frame courtesy of a break of 67 before stealing the third frame on the pink following a couple of gutsy pots on the colours.

Yan hit straight back with a classy century to ensure the scores were level at the mid-session interval, but Grace took command thereafter, runs of 70 and 59 doing the damage in frames five and six before he closed out the match with a fabulous century of his own, a masterful 104 that secured one of the biggest pay days of his career.

Grace told World Snooker Tour: "It's absolutely brilliant. I was really nervous at the start, I couldn't settle down. I dragged him down to my level really.

"I cleared up to go 3-2, made 50 odd in the next and won the last off his break. I finished alright in the end."

Trump sails into semi-finals

Judd Trump overcame a slow and scrappy start to beat Scott Donaldson 5-1 and reach the semi-finals.

After a brutal kick on the black ended Trump's counter in frame two and brought the scores level, there were signs that this might develop into an attritional affair which may well have suited the underdog more.

But three big contributions in succession, including his sixth century of the tournament, saw Trump change the terms of the contest and win it with plenty to spare.

Donaldson did not do himself justice when among the balls and will have been especially frustrated to have handed Trump several opportunities, including off each of his three break-offs.

It was fitting then that Donaldson's final shot was another break-off and again he left the simplest of openers for Trump, whose break of 86 might have been another century but nevertheless saw him cruise past the finish line.

Winner of the last two renewals, Trump remains on course to land a hat-trick and overcome the change in venue with this week's Home Nations event also taking place in Milton Keynes.

Next will be a clash with either Yan Bingtao or David Grace, followed by a potential rematch with Ronnie O'Sullivan - Trump's victim in the last two finals.

"Scott didn't really get going," said Trump, who felt the new cloth on the match table was behind his own sloppy start. "It was playing completely different than the first few games, a couple of times the side was acting the complete opposite as it was before.

"It took two or three frames to get used to, but I think when I got a rhythm going out there I felt comfortable."

Asked for his reaction to an almighty kick in frame two, Trump added: "The ball just went dead straight - it looked like I was playing a double!

"You can take that to heart sometimes, you feel like you're the unluckiest player in the world, it can get you down. You've just got to put it to the back of your mind."

Ever the showman, Trump beamed when asked about a stunning shot in the sixth and final frame, one which essentially ended what little hope remained for his opponent.

"All I'm thinking is 'if this goes right, everyone's going to love it backstage', that's all I'm thinking. They're the shots I enjoy. It wasn't easy to get into the pack from there.

"I like to hit the ball quite hard sometimes and when those shots come off they do look quite special."

In the second of the afternoon's quarter-finals, Carter came from 2-0 down to beat Kurt Maflin 5-3.

Carter didn't enjoy much rub of the green in the opening two frames as Maflin rode his luck to take the early advantage, but the tide turned after Carter reduced his deficit to 2-1 and he finished the match much the stronger.

Breaks of 50 and 91 saw Carter lead for the first time at 3-2 and though Maflin did respond to level, Carter always looked the more assured of the pair and he dominated the next two frames to book his place in the last four.

Carter told World Snooker Tour: "It's tough out there, I'm pleased to get through. My safety was good, I just kept trying to keep it tight and when I got my opportunities, I took them.

"I came here with zero confidence, in the nicest possible way I didn't particularly want to be here.

"It's easy to get yourself in a rut and get yourself in a big black hole. I gave myself a good talking to, and said 'come on, you've got to turn this round'."