Mark Williams has prevailed in a thriller with Ronnie O'Sullivan in the Masters quarter-finals, overcoming a three-frame deficit to win by a 6-5 scoreline.

With a number of big names having already been eliminated from the tournament at Alexandra Palace, the legendary pair went into their last-eight battle aware that the draw had opened up in their favour.

Although tournament favourite O'Sullivan looked on course to cruise into the semi-finals at one stage, Williams produced some sensational snooker to win the decider, posting his first victory over O'Sullivan in eight years in the process.

O'Sullivan was able to take the opening three frames, commencing the match with a 115 break and moving 3-0 ahead before Williams responded with 55 break.

The veteran Welshman built on that with an 83, and although O'Sullivan responded to reopen his two-frame advantage, Williams rolled back the years with a 143 break - his highest-ever effort in this tournament - to remain in contention.

That was backed up with a 90 break, and Williams moved to within one of success when he made a 59 clearance to edge the ninth frame.

While O'Sullivan was able to bounce back and take an absorbing contest into a decider, Williams put 30 on the board before going on to make a 102 break in a separate visit, much to the appreciation of the crowd.

Williams will now face either Hossein Vafaei or Jack Lisowski for a place in Sunday's final.