Ronnie O’Sullivan cut a frustrated figure despite fashioning a 6-2 advantage at the end of the first session of his World Snooker Championship quarter-final against Luca Brecel at the Crucible.

The seven-time champion took some time to settle and muttered “it’s a hard game today” after running out of position midway through a scrappy fourth frame.

O’Sullivan also thumped his leg in anger after missing a black in the seventh frame, but still managed to overhaul a 2-1 deficit and move within seven frames of sealing his place in the semi-finals upon their resumption on Tuesday evening.

A quickfire session looked in store when Brecel opened proceedings with a break of 93 and O’Sullivan responded with a fast 56 which proved enough despite a rare missed black off its spot.

Another error from O’Sullivan served up Brecel for a frame-winning break of 68 to move in front, and only a tenacious 35 clearance in the next allowed O’Sullivan to edge in at the mid-session interval all square.

It was Brecel’s turn to feel frustrated after the restart as a series of costly errors from the Belgian put the momentum firmly in O’Sullivan’s hands.

A break of 59 sent O’Sullivan in front for the first time before Brecel was punished for scattering the reds in the sixth frame as the favourite reeled off an effortless 128 to move two clear at 4-2.

Brecel did all the hard work in the next, getting the two snookers he required for an improbable steal, only to jaw a relatively simple pink as he sought to clear, handing O’Sullivan a 5-2 advantage.

Brecel missed a black off its spot in the final frame of the session and O’Sullivan needed no second chances to mop up with a break of 85 and leave himself well and truly in control.