Ronnie O'Sullivan crashed out in the first round of the UK Championship after a 6-4 defeat to Zhou Yuelong.
O'Sullivan, who celebrates his 50th birthday on Friday, missed a chance to force a decider and Zhou cleared the colours to claim his first win over the record eight-time champion in eight attempts.
It marked the first time O'Sullivan, who now resides in Dubai, has played in Britain since his loss to Zhao Xintong in the World Championship semi-final in May.
And he revealed he has no particular plans for his big day as he prepares to head straight out of York and back to his temporary base in Ireland.
"I'll probably go for a run, eat some nice food, and watch some snooker," shrugged O'Sullivan, who insisted he was not particularly downbeat despite a hard-fought defeat.
Referencing his imminent move into his sixth decade, O'Sullivan added: "It feels all right. It feels good in some ways and not so good in others. You probably worry less about some of the stuff you used to worry about, and try to enjoy your life.
"I think since the start of the tournament I've enjoyed playing. (But) that was a bit of a ropey performance. I missed a lot of balls and I didn't deserve to win."
O'Sullivan clawed back a two-frame deficit but Zhou, the world number 29, stole two frames on the black to regain his momentum, and the favourite's hopes of forcing a decider evaporated when he broke down on the yellow and Zhou ultimately cleared the colours for the highest-profile win of his career.
Mark Selby shrugged off a minor revival by his Chinese opponent Lei Peifan to secure a 6-2 win and set up a last-16 clash against Zhou.
