John Higgins reached his first ranking tournament semi-final since October 2001 but Steve Davis pushed him all the way in a gruelling Irish Masters quarter-final.
Higgins eventually came though 6-4 to record his 18th straight win over Davis.
The Scot opened with 110 and although he could only manage a best of 34 in the next three frames, still led 3-1 at the interval.
Frame five was a key moment as Davis was well set to reduce his arrears.
But in shifting a red tight to a side cushion he couldn't complete his first objective of potting the black and Higgins duly made it 4-1.
Davis won the sixth without conceding a point but went three down with four to play in losing the next.
Despite losing frame eight, Higgins should have won the match at 6-3 but gave Davis new belief when he missed the final green in frame nine.
Davis was in first as well in the 10th but after sinking the first red he played his last shot by missing the pink.
Higgins now faces Dave Harold in the semis.