Ronnie O’Sullivan maintained his winning form at the World Grand Prix after Ali Carter had earlier continued the pair’s bitter war of words by saying he does not think the world number one is “that well mentally”.

O’Sullivan was back in action 48 hours after beating Carter in Sunday’s Masters final, where both men carried on a long-standing feud.

The world number one, who was a 4-2 victor over Pang Junxu in Leicester, is under review by the World Snooker Tour after he described Carter as “a f****** nightmare” and said he needs to “see a counsellor” after beating his fierce rival.

The 48-year-old was hitting back at Carter, who claimed the seven-time world champion had “snotted on the floor” during their match at Alexandra Palace, which O’Sullivan won 10-7.

Both men are in action at the Morningside Arena this week and Carter went back on the offensive ahead of his 4-3 win over Wu Yize, telling ITV4: “Ronnie is entitled to his opinion. I just said what it is and how it was and I talk facts. It is as simple as that.”

Asked whether he was angry at O’Sullivan’s comments, he said: “Angry about what? It makes no difference to me what he says. He says different things on different days. I don’t think he even knows what is going to come out of his mouth at certain times.

“I actually feel a bit sorry for him. I don’t think he is that well, mentally. So we move forward and we go again this week.”

O'Sullivan went on the rampage against Carter after Sunday's Masters final O’Sullivan, pictured, went on the rampage against Carter after Sunday’s Masters final (Bradley Collyer/PA)

O’Sullivan caused a stir when told several newspapers: “He needs to sort his f****** life out. I’m not going to skirt around it any more, tip-toeing on eggshells around someone like that. He’s a f****** nightmare.

“Playing snooker against someone like that is a nightmare. He’s not a nice person. It’s not a nice vibe he leaves around the table.

“I’ve said my piece, I don’t give a s***. I’ve said it now, done. You know what he’s like, everybody knows what he’s like.

“He’s got issues. F****** why has he got issues with me? I’m not having it.”

O’Sullivan admitted he should have withdrawn from the event in Leicester and said the only reason is still playing tournaments is to keep his tour card.

He said on ITV after his win against the Chinese: “I will definitely be missing a few tournaments after this, I shouldn’t even really have come here to be honest, but it is alright so I thought I would just turn up. In hindsight, I shouldn’t have come.

“The main thing for me now is exhibitions, I am contracted to 25 a year so I have got to make time for them, I have 25-30 days with my sponsors, that’s two months where it is important stuff for me.

“I just play and perform to make me get my cue out of the case basically, if I didn’t have tournaments I wouldn’t play.

“I would like to think if I fell off the tour I might get a wild card but knowing World Snooker they would probably say no. I am just trying to keep my tour card really, that’s all I am trying to do.

“I am not bothered about tournaments, it is not my favourite bit to be fair.”