UK Championship 2014: Ali Carter loses to Zhang Anda in first round

Carter will be seeded 13 for the remainder of this season, the ranking he held when he began cancer treatment

Ali Carter's first ranking event appearance since having treatment for lung cancer in May ended in a shock 6-5 loss to Chinese player Zhang Anda.

Carter received a standing ovation beforehand and led 4-2 and 5-3, but Anda made breaks of 50 and 100 before winning a scrappy final frame.

Four-time champion Ronnie O'Sullivan defeated Welshman Daniel Wells 6-2, despite playing with a broken ankle.

Mark Williams, Ken Doherty, Mark Allen and Neil Robertson also progressed.

And Shaun Murphy showed good composure to win five straight frames from 3-1 down and defeat former world number three James Wattana.

Defending champion Robertson was not entirely happy with his performance but still thumped Leicester amateur Joe O'Connor 6-0.

Carter had seemed set to take his place alongside the Australian in the last 64 after going 5-3 up against a player seeded 116 for the tournament.

But the 35-year-old was understandably a long way off the sort of form that has seen him reach two World Championship finals.

"It was a terrible performance from me from start to finish," said Carter, who won the General Cup title in Hong Kong last month. "It was abysmal.

"It's a long way back after what I have been through over the last six months. I have serious work to do.

"It was embarrassing to play that bad. I will have to go back to the drawing board and I am looking forward to the Masters."

In the morning session, two-time former champion Williams coasted past teenager Steven Hallworth 6-1 despite playing with a neck problem.

And veteran Irishman Doherty scored three centuries in a smooth 6-2 victory over Mitchell Mann.

"I was happy with the way I played scoring-wise," Doherty said.

"Not many players will score score three centuries in the first round. That always gives you confidence. It's good to put in a good performance."