LONDON — Snooker legend Ronnie O'Sullivan's 44th birthday celebrations went flat with a surprise 6-4 defeat by Chinese star Ding Junhui in their last 16 clash at the UK Championships in York on Thursday.

Ding has struggled for form over the past two seasons with his last ranking title success the World Open in September 2017.

However, the 32-year-old — who has slipped to 16 in the world and reached just one quarter-final in a ranking event last year — looked like he might be rediscovering some of his old élan.

He swept into a 4-1 lead — including breaks of 81 and 110 — before five-time world champion 'Rocket' Ronnie got into his stride and leveled at 4-4.

Ding closed out the match and sealed a last eight meeting with his compatriot Liang Wenbo by taking the next two frames for what was only his second ever win over O'Sullivan.

"Ronnie played fantastic but it's a really big win for me," said Ding, who has won the UK Championship twice though the last time was back in 2009.

"I am very happy. I knew his comeback was on the way."

Ding had to scratch his head when asked the last time had played as well as he had done against O'Sullivan.

"I can't remember!" he replied.

O'Sullivan — who had been seeking a record-extending eighth UK Championship title — said he went away content he had made a fight of it.

"I am quite happy with four frames," said O'Sullivan, who had won the last two editions of this tournament.

"I was 4-1 down and he hadn't missed a ball and I was thinking this could a 6-0 or 6-1 mauling on my birthday.

"I got it back to 4-4 and twitched a red and he played well and held himself together at the end.

"He's a great player, for him not to have won the world title is a bit of a surprise.

"I'm sure with his quality and pedigree and his will to win, that will start to fall into place at some time." — AFP