Ronnie O'Sullivan held off a determined fightback by Ding Junhui to book his place in a record-equalling 13th Masters final at Alexandra Palace.
O'Sullivan surged into a 4-0 lead at the mid-session interval before the Chinese star responded by winning the next three frames.
Ding scored two successive centuries including a near-miss on a 147 when he cleared reds and blacks but missed a difficult green.
But O'Sullivan replied with the two frames required to win 6-3 and move closer to becoming the first player to win any one of the 'triple crown' events eight times.
O'Sullivan told BBC Sport: "I don't buy into numbers or achievements, I just enjoy what I have and am grateful for what I have.
"I understand that the western philosophy is about getting more and more is never enough, but I don't adopt that."
Judd Trump saw off Neil Roberton 6-4 to progess to the decider after an error-strewn match with occasional quality.
What a match against my brother Ding. The guy is amazing and a class act on and off the table. A real asset to the game 👑 not easy playing against someone so close to you but delighted to get through to my 13th Masters final 🏆 pic.twitter.com/iU3gkWqGem
— Ronnie O'Sullivan (@ronnieo147) January 19, 2019
