O'Sullivan and Vafaei were meeting for the first time since their eagerly-anticipated grudge match at the World Championship earlier this year, when the Iranian smashed the pack of reds on his first break-off shot.
There was plenty of respect shown between both players on Saturday, with the pair exchanging words at the end of the match as O'Sullivan reached his ninth UK Championship final.
O'Sullivan, known as The Rocket, has won the event, which is snooker's second-biggest ranking event behind the World Championship, a record seven times - most recently in 2018.