Mark Selby bounces back against Ronnie O'Sullivan after second World Championship session

O'Sullivan, the five-time former champion, had led 5-3 after the first session on Wednesday evening, and could well have gone into Thursday's action 6-2 up after letting a chance slip in the final frame.

And Selby was once again able to draw 'The Rocket' into a lengthy battle in the opening frame of the second session.

O'Sullivan had briefly threatened to rifle through the frame, but an unfortunate kick on the black allowed Selby to elongate it, with both players trading safeties until the 44-year-old's patience was finally broken and his younger opponent cleared the table.

The second frame was a much quicker affair, with Selby making a break of 97 to draw level and he was similarly surgical when presented with an opportunity by O'Sullivan in the third frame of the day, converting a fantastic long pot on the final red before building an unassailable lead to move 6-5 ahead.

O'Sullivan was left to rue his profligacy once more as Selby won his fifth frame in a row to extend his advantage to 7-5.

"At the moment, Selby is firing on all cylinders and O'Sullivan is not. And if he doesn't get going then he's going to be in a bit of trouble," said Jimmy White on Eurosport during the mid-session interval.

"He hasn't potted any balls since yesterday."

O'Sullivan started the 13th frame with another error on the brown, but Selby was unable to punish his rival. The five-time champion returned to the table and produced a break of 87 to arrest the momentum against him.

But his comeback was temporary, with Selby punishing a missed blue to restore his two-frame advantage.

O'Sullivan kept in touch by tempting Selby into an error on a tricky red, then taking advantage with a break of 82. He looked to be away in the final frame of the day's play but a miss on a tricky pink allowed Selby to hammer home his dominance in the session and turn his 5-3 deficit into a 9-7 lead.

O'Sullivan was visibly frustrated and punched the table after his miss and is most certainly up against it ahead of Friday's resumption.