Ronnie O'Sullivan pegs back Stephen Hendry

Ronnie O'Sullivan put an uncertain start behind him to share the opening eight frames of his 888.com World Championship semi-final with Stephen Hendry at the Crucible Theatre in Sheffield.

O'Sullivan, twice world champion, won the last three frames of the first session after falling 4-1 behind to the Scot, who has lifted the title seven times.

Hendry's total clearance of 140, his second-highest break of the season, clinched the first frame inside 15 minutes, and he took three of the next four, O'Sullivan breaking his duck in frame four when he left his opponent needing snookers on the pink.

O'Sullivan broke down in the fifth frame on 64 - eight reds and eight blacks - and Hendry's run of 41 left him 23 points behind with the colours remaining.

The Hendry of yesteryear would have cleared up, but he missed a straight yellow and was left to scrap it out with O'Sullivan before eventually leading 4-1 when he managed to clear from green to black.

At this stage, O'Sullivan had not given a glimpse of the form that had carried him this far, reducing the odds on the Londoner to win the championship from 7-2 to 10-11. Hendry, however, was soon to find out how O'Sullivan would react to his flying start.

Hendry was quickly 32-0 ahead in frame six but, after conceding 24 penalty points, he stayed in his chair as O'Sullivan compiled a break of 102 - his fifth century of the championship and 42nd of the season.

Only Hendry, with 53 and 51, has recorded 50 or more centuries in any season. O'Sullivan's best, 48, was during 2006-07.

Now only two behind, O'Sullivan set about going to his lodgings at 4-4 overnight and, in the space of 33 minutes, he did just that.

Frame seven produced little resistance from Hendry, who potted only one red as breaks of 32 and 31 helped to carry O'Sullivan well out of sight before the colours were reached.

The final frame brought uncharacteristic errors from both players. O'Sullivan was first in, but having put together a break of 46 he missed the black. Hendry replied with 34, but went in-off attempting a double and next season's world No?1 returned to the table to put the frame beyond doubt and level at 4-4.

The semi-final continues today, when 16 more frames will be played, with the final nine tomorrow.

Before yesterday's match, Cliff Thorburn received a silver salver to mark the 25th anniversary of his feat in achieving the first world championship maximum.