By John Curtis, PA Sport

John Higgins lost his cool in his Embassy World Championship semi-final with Mark Williams but stormed back in typical style to keep alive his hopes of a second title in three years.

Higgins' frustration at being uncharacteristically out-of-touch boiled over at the end of the fourth frame of the second session at the Crucible Theatre.

The Scot stormed out of the arena after missing a relatively easy pink into the centre pocket and conceded the frame to Williams when only 53 points behind and a possible 67 still on the table.

He headed straight to the practice table with Williams in the driving seat at 7-5 ahead in the best of 33 frames contest. And the work Higgins put in during the 15-minute break paid dividends as he took the last three frames to level the match at 8-8.

It keeps alive his chances of avenging last season's 17-10 semi-final defeat by Williams - with the winner meeting Matthew Stevens or Joe Swail in Sunday's final.

Play never rose to the anticipated heights throughout the eight-frame session but Higgins in particular struggled before the interval against his Welsh opponent.

Williams won the first with two breaks of 35 and then runs of 31 and 34 gave him the second but in both frames Higgins had been guilty of missing the type of balls he would normally bury in the pockets.

He won the 11th with the aid of a 30 break but then came his surprising outburst in conceding the next after a 60 from Williams had put him in the driving seat.

The picture did not instantly improve for Higgins with a run of 78 from Williams extending his advantage to 8-5.

But Higgins at last found his touch in the 14th and for the time in the session he looked confident and composed with a break of 73 proving decisive.

Williams was first amongst the balls in the next with a 37 but Higgins responded with a 48 and a 32 clearance to take the frame.

The final frame of the session was a scrappy affair but an opening 31 followed by another 26 was another to see Higgins home and back on level terms.

The match will resume on Saturday morning and will then be played to the finish on Saturday evening.