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RESULT: John Higgins 10-7 Joe O'Connor - Table Two
END OF SESSION: Si Jiahui 6-3 David Gilbert - resumes Tuesday evening
END OF SESSION: Ding Junhui 6-3 Zak Surety - resumes Tuesday afternoon
First-round matches are best of 19 frames
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Si 3-2 Gilbert
Si Jiahui in first, David Gilbert takes the frame?
Well almost a carbon copy of the fourth frame except the Englishman can't knock in a difficult pink which allows Si to tidy up.
Higgins 7-6 O'Connor
Steve Davis
Six-time world champion on BBC Four
Joe O'Connor will be pleased to have got some table time. He has spent a lot of the evening in his chair or bolted to the cushion.
Higgins 7-6 O'Connor
The 13th frame of this match is a longish one after a re-rack.
But Joe O'Connor takes it. A very timely frame for the Englishman as he heads back to relax and grab a drink in his dressing room for the next 20 minutes or so.
Si 2-2 Gilbert
David Gilbert gets back level at the mid-session interval with a timely run of 58, the highest of the match so far.
Higgins 7-5 O'Connor
Steve Davis
Six-time world champion on BBC Four
Joe O'Connor is going through the mill out there now against one of the greats of the game.
Si 2-1 Gilbert
Over on table two David Gilbert is up and running, with a run of 55 helping him get over the line.
Higgins 7-5 O'Connor
John Higgins misses a couple of early long-range reds and then is left another which is arguably the hardest of the three. So of course he sinks it.
It is hardly the easiest break he has made but 'The Wizard of Wishaw' simply refuses to leave the table and ends up registering the 1,035th century break of his career.
Si 2-0 Gilbert
David Gilbert was looking like he was about to mop up and take the second frame but he rattles the jaws of the top left corner again with a tough red that really should have been played dead weight.
Si Jiahui capitalises to move two frames to the good.
Higgins 6-5 O'Connor
John Higgins is yet to register a break of 50 in this match but he edges in front with some excellent match-play snooker.
Si 1-0 Gilbert
Si Jiahui takes a topsy-turvy opening frame.
David Gilbert looked to be in charge of that frame after potting the green and being on the brown to the top left corner but he left it when he rattled the jaws.
Higgins 5-5 O'Connor
Stephen Hendry
Seven-time world champion on BBC Four
John Higgins looks a completely different player this evening. The body language, the way he is striking the ball, he just looks a lot more positive.
He may not have won the frame in one visit but it has been very impressive and the best frame he has played in the whole match.
Higgins 5-5 O'Connor
John Higgins is looking pretty good as he races to 37 but he inadvertently knocks in a red while splitting the pack off the blue.
The one bonus is he has not left Joe O'Connor with a pot and when he gets back to the table he rolls in another long red, followed by a tricky brown to the middle.
He is on a roll and secures the frame to draw level.
Higgins 4-5 O'Connor
Stephen Hendry
Seven-time world champion on BBC Four
Coming into this Championship with two wins under his belt which he hasn't had the last two or three years has probably put a bit more expectation on this from himself.
He probably fancies himself more this year than in recent times so tonight it is just about getting to 10 for John Higgins.
The players are out. The partition is down and we are about to get under way.
Si v Gilbert
Image source, Getty ImagesStill only 22, Si Jiahui must be regarded as one of the best Chinese hopes to win the World Championship.
Ranked 13th in the world, Si's run to the semi-finals a couple of years back involved winning three qualifiers and then seeing off the likes of Shaun Murphy, Robert Milkins, and Anthony McGill.
However, he was unable to stay the course against an inspired Luca Brecel, who went on to become champion.
England's David Gilbert produced some of his best snooker in Sheffield just 12 months ago when he reached the last four, so this could be an intriguing encounter.
Higgins 4-5 O'Connor
Image source, Getty ImagesFour-time world champion John Higgins has looked rejuvenated since claiming his first ranking title for four years at the World Open in March, where he defeated Joe O'Connor.
A more recent triumph at the Tour Championship where he delivered a vintage display to overcome Mark Selby in a high-quality final, suggests Higgins is in excellent nick, albeit he was 7-2 up after nine frames against O'Connor in their previous meeting.
This time 12 months ago O'Connor saw off another four-time winner in Selby. Could he repeat that feat this evening?
Text updates will resume on this page from about 19:00 BST, when you can also watch live coverage of both first-round matches by clicking on the "Watch and listen" tab.
All times BST and matches are best of 19 frames
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Ding 6-3 Surety
John Parrott
1991 world champion on BBC Two
Now you know why he qualified - because he played like that in the qualifiers, knocking balls in from everywhere and making loads of centuries. I'm really pleased for him that he's showed that.
Ding hadn't really been tested because Zak hadn't produced anything like that this afternoon. But if he produces more of that tomorrow, who knows?
Ding 6-3 Surety
Zak Surety must have wished he had started the match like this.
A fine long red to get going and the cue ball on a string as he crafts his first ever Crucible century.
A break of 104 earns him a standing ovation and possibly a way back into this match when it resumes on Tuesday afternoon.