Ronnie O’Sullivan admitted his motivations have changed when it comes to winning the World Championship after easing into the quarter-finals with a 13-5 victory over Matthew Stevens.

The five-time world champion needed to win only one frame to book his place in the last eight where he will face Stuart Bingham, although Stevens, who was suffering from a neck injury, won the first frame of the final session before O’Sullivan powered through.

Trailing 12-4 from Sunday, Stevens cut the gap to seven frames with a break of 63 before his 39-year-old opponent ended the contest in the next with a run of 77.

Following the relatively simple conclusion to the match O’Sullivan revealed he has a much calmer approach in his attempt to win a sixth world title.

“Matthew had a really bad neck and I know what it’s like to play with a bad neck. He couldn’t even get down on the shots so it was a bit difficult to watch your opponent suffering like that,” O’Sullivan said.

“It was hard for Matt there, so it was hard for me to get motivated. I know I only needed one frame so there was no adrenaline there. I just kind of had to get something and get the one frame I needed.

“I’m still happy to be in the tournament and, if I can find a bit of form, then I’ve got a chance. It’s still good to be in the tournament.”

When asked if he still felt the same buzz going for his sixth world title as he did for his first, O’Sullivan said: “No, not really. When you’ve won it five times and you’ve won everything else, then you don’t really get that excited about it.

“For me I’m just happy to still be playing but nah, I don’t get excited like I used to when I was going for one, two, threes and fours. You’re just kind of hungry for it.

“I’ve kind of settled at five. It’s not a bad innings and, if I can add to that, that’s great but you kind of lose motivation in the end. It’s not the same kind of motivation, it’s a different kind of motivation. A lot calmer, more relaxed about everything.

“There’s no pressure on me to win another one but it would be nice. It’s a different type of pressure, I suppose.”

In the other match which finished in the evening session Neil Robertson came through 13-5 against Ali Carter to line up a last-eight meeting with Barry Hawkins.

Robertson crossed the line in style with a break of 145, the highest in the tournament so far, to claim victory after leading 11-5 overnight.

The world No6, Judd Trump, is also through to the quarter-finals after completing a 13-8 win over Marco Fu with a brilliant century. Trump, the 2011 runner-up, rattled off a complete clearance of 133 to end the resistance of Fu and book a date with Ding Junhui.

Asked about his performance, Trump told BBC Sport: “It was solid. There was nothing too extreme – a few dodgy sessions in the middle of the match where I could have probably closed it out but other than that I think I was quite solid from start to finish.

“Marco changed his game plan and went for everything towards the end, so that made it quite difficult but I am pleased how I closed out the match.”

On his overall prospects, he said: “I am very confident in my game this time. I know if I keep it up I have got a good chance but it only takes one bad session at this level. You have got to be consistent every single day.”

The world No8, Shaun Murphy, the 2005 champion, reached the quarter-finals for the eighth time by finishing off Joe Perry 13-5, albeit in scrappy fashion. Murphy, leading 12-4 overnight, fell below the high standards he set earlier in the match but, after losing the day’s opener, eventually edged home in an awkward, error-ridden 18th frame to line up a meeting with the tournament’s giant-killer, Anthony McGill.

Murphy said: “It is just nice to get through and still be punching. You’ve got to treat the game with respect and hope you get the opportunity to get over the line.”