Ronnie O'Sullivan gained the early initiative by moving into a 5-3 lead in his grudge Embassy World Championships semi-final Stephen Hendry at The Crucible.
Defending champion O'Sullivan won the final two frames of a tense opening session with seven-time winner Hendry to edge ahead.
O'Sullivan gave the best-of-33 frame contest added spice by launching a strong attack on Hendry in a dispute stretching back to the 1999 world semi-final meeting between the pair.
He said he would "love to stick it right up Hendry" and that "the most satisfying thing for me would be to send Stephen home as quickly as possible to Scotland so he can have a nice summer off!"
The Rocket was far from happy after being called for a miss in the 1999 clash and then Hendry insisted he play the shot again. As a result of that incident, O'Sullivan said Hendry had gone down in his estimation and that he had "lost a lot of respect for him".
The pair did at least maintain the appropriate etiquette by shaking hands before the last-four showdown which is scheduled to span three days and four sessions.
O'Sullivan, an odds-on favourite with the bookmakers to reach the final, began in impressive fashion with a break of 115 to take the opening frame.
Hendry levelled in the next with the aid of a run of 33 but O'Sullivan, helped by a fluked black into the centre pocket, edged back in front in frame three.
The final frame before the mid-session interval was a more dramatic affair with Hendry opening up with a break of 65 but then missing a straightforward red into the centre pocket.
O'Sullivan responded with a 63 but left himself a difficult final black which he over-cut after leaving himself too straight on the pink to gain good position. Up stepped a relieved Hendry to level for a second time.
The first two frames after the resumption were also shared. O'Sullivan went ahead for the third time after completing a 37 clearance only for Hendry to again respond with a run of 73 to the pink. But Hendry failed to pot a ball in the final two frames as breaks of 63 in the seventh and 99 in the eighth put the Essex man in control.
