Mark Williams' reign as Embassy world champion could end in Sheffield on Saturday morning.

The world number one re-starts against Joe Perry with a 10-6 deficit and has only just avoided defeat with a session to spare.

Perry has taken both opening sessions 5-3 and requires only three of the remaining nine frames to cause another major shock.

Perry was 250-1 to win all eight of this afternoon's frames but the odds came tumbling down as he captured the first four.

Williams ensured the pair must return tomorrow by outscoring his opponent 162-0 over the next two.

But Perry looks determined to reach the quarter-finals for the first time in his career. The former European and China Open finalist clinched a scrappy 15th frame as Williams still could not find any inspiration.

The Cardiff-based player did manage to reduce his arrears to more manageable proportions in the last frame of the afternoon.

However, it remains touch and go whether he will still have a hold on the trophy on Saturday.

No player has retained the title since Stephen Hendry in 1996 and at the moment Williams has his work cut out just to reach the last eight.

He became a father for the first time exactly a week ago and scraped through his opening match against fellow Welshman Dominic Dale.

A week at home with fiancee Joanne Dent and baby Connor has not enabled him to find an extra gear for his game and it is going to take a monumental effort to rescue the match.