One table, four players and two world champions remaining. And so the focus sharpened in the Crucible. On the face of it, yesterday's semi-final line-up was a choice between a match with two highly public figures or one between two talented snooker players, who even John Parrott might have had difficulty in identifying in any Know Your Sport pick-a-number-round. Spice or potatoes and veg.

Mark Williams and John Higgins may be the first and fifth best players in the world, but the duel between Stephen Hendry and Ronnie O'Sullivan represented far more after day 13 at the Embassy World Championships. And in that match Hendry drew first blood taking a 6-2 overnight lead.

Two reputations at odds with their owners, Hendry desperate to reclaim the high ground he once occupied, O'Sullivan anxious to disprove his image of being able to flash up a maximum 147 break more easily than he could grind out a championship win.

Six-time winner Hendry, embraced more warmly this year since he discovered a disconcerting vein of vulnerability to off-set the iced-water image, against an occasionally hot blooded O'Sullivan was indisputably yesterday's eye catcher - and Hendry lived up to the bill in the opening exchanges.

Rattling off a 127, 82 and 86 to no reply from O'Sullivan, the former champion, a believer in intense concentration, eclipsed the third seed to the extent that it took the forlorn O'Sullivan 36 minutes and 57 seconds to register his first points in the match.

Even then it was an unfortunate kick of the green that sent Hendry's white ball into a corner pocket and let the 23-year-old from Essex onto the table after he had opened by being off target with relatively straight pots.

In the fourth frame Hendry was 30-0 up and cruising towards another success before O'Sullivan conjured a break of 78.

But Hendry kept the pressure on O'Sullivan, winning the next three frames before O'Sullivan snatched the last to close the gap to just four.

And that is likely how the game may continue, Hendry steely and assured, O'Sullivan surging in colourful flourishes but liable to choose a difficult pot rather than resort to safety.

Hendry has his sights on a record seventh world title. O'Sullivan has yet to reach the final but is bidding to become the first English player to win the title in eight years.

Higgins, hoping to become the first debutant champion to come back and win the tournament in the following year, became involved in the predicted slugfest with one of the best potters in the game.

Typically, defensive play came into the game only in the greatest of emergencies as the two stood toe to toe, bringing their combined plus century breaks to 13 for the tournament, with Higgins leading 7-6 on that count.

In the first four frames the two players returned breaks between them of 72, 45, 47 and 104, the half session ending 2-2.

With Williams stealing a march in the final four frames to take an overnight lead of 5-3 on the champion with breaks of 101, 66 and 92 to Higgins's 126, the scores demonstrated, if nothing else, how perilous it was and will be over the next two days for either player to let the other take the floor.

Higgins was behind at the end of a session for the first time in this year's championship.

He dropped just 12 frames on the way to the semi-final.

Williams is aiming to improve on last year when he was beaten by Ken Doherty at the semi-final stage.

Doherty has slipped from fourth in the world rankings to seventh according to figures released yesterday by the sport's governing body, the WPBSA. Fergal O'Brien is placed 11th on the list.

Order of play Today

10.00 a.m.: J Higgins (Sco) v M Williams (Wal), Williams leads 5-3, eight frames to play.

2.30 p.m.: S Hendry (Sco) v R O'Sullivan (Eng), Hendry leads 6-2, eight frames to play.

7.00 p.m.: Higgins v Williams, eight frames to play.