Ronnie O’Sullivan v Si Jiahui LIVE: Score and updates from World Snooker Championship

O’Sullivan surprisingly misses frame-ball again. A glimmer of hope for Si but he’ll need a total clearance from here.

Hmmm, he pots a red but then promptly misses the pink. Not great. And he immediately concedes the frame.

Ronnie O’Sullivan wins frame four and leads 3-1 at the mid-session interval

O’Sullivan moving the cueball around nicely, mainly being forced to work with the blue as the black is tied up. Judging the pace of each shot really nicely.

The lead builds past 30 points, then 40. Good work so far by the Rocket here.

Head in hands from O’Sullivan who, despite his lead, doesn’t seem happy out there. He misses a very makeable red along the bottom cushion as it hits cushion first.

Laaves Si in among the balls but he can only pot one red before missing a thin cut on the black. He needs to start punishing the Rocket’s mistakes while he’s under pressure

Good split of the remaining reds from the Rocket. They’re all there for the taking now.

He moves ahead of Si’s score with one red remaining and the only real obstacle left is the brown on the top cushion. Leaves a relatively thin cut on the brown but drops it into the pocket and lands nicely on the blue, clearing the remaining colours for a 71 break.

Nicely done by Ronnie O’Sullivan to win frame three and lead 2-1 but Si Jiahui was in control of that frame and let it slip.

The cueball is wandering a bit for Si during this break but he keeps potting the balls to stay at the table. Until he doesn’t…

With his break at 30 he misses a red to left corner, overcutting it. Big opportunity missed.

Si leads 44-12 but O’Sullivan back at the table, in the balls.

O’Sullivan hasn’t settled properly here. Switches to play left-handed for a red down the cushion but it’s a deceleration and he misses it. Hangs his head in frustration. Leaves Si right in among the balls.

Good break-off by O’Sullivan and it forces a safety mistake from Si, so the Rocket is in first with a long red. But soon breaks down on just 6 points, giving Si a chance.

The Chinese star will hope to get a few points here with four or five loose reds but soon runs out of position. Takes on a thin snick to the corner but misses it by a distance. Leads 14-6 but he’s stuck the red up for Ronnie

Nice cannon on the reds after potting a black and the frame is at Si’s mercy as he passes 50 points. Just need to keep his composure for a few more pots.

Tough pot on a red when he’s on 60. Good recovery shot, goes up for the green.

He’s rolling now and gets over the line in the frame. Can he complete the century? He does. The final green takes him to 100 and although he then misses the brown, it doesn’t matter.

Si Jiahui wins frame two to get on the board at 1-1.

Maybe Si is starting to find his long game in frame two. Digs out a nice long pot to the left corner, dropped in.

The black follows and this is a good scoring chance. He has to let O’Sullivan know he’s in this match.

A fun safety exchange with fluked snookers and the cueball rebounding off the jaws of pockets brings oohs and ahs from the Crucible crowd.

Eventually O’Sullivan pulls out a long pot on the red and then pots the pink to leave Si needing snookers. Clears up to the blue for good measure and Ronnie O’Sullivan wins a very scrappy opening frame to lead 1-0