Neil Robertson avenged his World Grand Prix final defeat by dumping Ronnie O'Sullivan out of the Masters quarter-finals and will now face Mark Williams in the last four.

Australian Robertson prevailed 6-4 to book a last-four spot, handling a partisan Alexandra Palace crowd and hitting back after losing 10-8 to O’Sullivan in December’s Grand Prix showdown in Coventry.

Seven-time Masters winner O’Sullivan mustered just one century in the match but still levelled at four frames apiece, before Robertson pulled away.

Robertson’s top breaks were 119 and 130, and he will now face Williams, who edged out John Higgins 6-5.

"I know how much a Masters crowd can really carry a player, my Masters debut was against Jimmy White," Robertson told the BBC.

"So it was important I was able to hit back against him. I knew I was going to hit the ball well today.

"You never know what the result’s going to be, but I knew I would hit the ball well.

"I pulled off some brilliant pressure shots and gained momentum from that. It’s nice that I can still pull out the recoveries when I need them."

O’Sullivan lamented the middling standards of both players, but refused to offer any excuses despite biting the tip off his cue straight after his defeat.

"It wasn’t, really, good stuff; I didn’t play good, he didn’t play good," O’Sullivan told the BBC.

"Both of us were queueing alright. I was just trying to make it as competitive as I could, and trying to give the crowd and give Neil a bit of a game."

Asked about problems with his cue tip, O’Sullivan added: "I never make any excuses, Neil was the better player today.

"Hopefully he goes on and wins it. I like Neil, he’s a good man."

Williams needed a nerveless 91 break in the deciding frame to inch past Higgins on Thursday night.

The Welshman immediately paid tribute to the crowd, insisting he could not recall a better atmosphere.

"I’ve never experienced anything like that, the crowd was unbelievable," Williams told the BBC.

"I couldn’t feel my legs in the chair, that’s the best intro I’ve ever had, I think John would say the same.

"So thanks to all the crowd because it made the occasion all the more special."