World champion John Higgins saw off a resilient Neil Robertson and world number one Ronnie O'Sullivan eased past Peter Ebdon as both men booked their place in the last eight of the UK Championship.

Higgins won a thrilling contest with Robertson 9-8 having earlier compromised a 4-1 lead to let his opponent back in.

Robertson opened the evening session with breaks of 127 and 78 to level things up, but Higgins again did enough to go back into the lead at 8-6.

But nerves appeared to affect Higgins and he made a couple of errors to once again open the door for Robertson.

Higgins, who lost out to the same opponent in a memorable semi-final in October's Grand Prix, held his nerve in the decisive final frame.

O'Sullivan extended himself slightly less, hammering Ebdon 9-3.

"Every time I came to the table, the balls were in unusual positions and the colours were off the spots, so I was thinking 'where do I start'? It felt like a war and I found it difficult to get any momentum. I'm not getting excited over winning or losing, I'm just staying in neutral. I'd rather be hitting form and getting excited," O'Sullivan said.

He produced two hundred-plus breaks in the afternoon on his way to a 6-2 lead before taking three of the next four to secure his spot in the quarter-finals.

Higgins will face Liang Wenbo, who dispatched Mark King 9-2 in an effortless display, in the last eight today.

O'Sullivan has been pitted against Mark Selby following his 9-5 win over an off-colour Stephen Hendry.

Other results: Carter leads Ding 7-5; Maguire leads Lines 7-5.