Ronnie O'Sullivan is set to end his snooker exile and defend his world title in April this year, the Englishman said at a news conference in London yesterday.

Four-time world champion O'Sullivan, 37, has played only one competitive match this season after growing disenchanted with snooker and had until the end of February to decide whether to defend his title before the entry list closed.

As reigning champion, O'Sullivan will be the top seed at the World Championship, which starts at the Crucible Theatre in Sheffield, northern England, on April 20.

And he insisted a lack of match practice was no reason to disregard his title chances, saying: "I just thought it was time to come back. I have a different perspective now."

He added: "I am used to being written off. I know how good I am and that I can do this."

O'Sullivan has played just once since winning his fourth world title in May - an uninspiring loss to the previously little-known Simon Bedford at a minor tournament in Gloucester, England.

"Three or four months ago I was sitting thinking that I would rather be losing 10-0 in Sheffield to be back playing, rather than going for lunch, dinner and chilling out," O'Sullivan said.

"I got bored and had to get back to playing, winning or losing, and it shows how big a part of my life snooker is."

In Haikou, China, defending champion Mark Allen scored a 5-2 win over Ryan Day at the Haikou Open.

In another match, Chinese rookie Zhao Xintong beat Andrew Higginson, who is ranked 25th in the world, 5-1. Meanwhile, Shaun Murphy sent Martin Gould packing with a closely contested 5-4 win.