World Championship 2017: Ronnie O'Sullivan pegged back by Gary Wilson
Five-time champion Ronnie O'Sullivan was pegged back to a 5-4 lead over debutant Gary Wilson in the first round of the World Championship on Saturday.
Former taxi driver Wilson fell 5-1 behind but took the last three frames of the session, including the ninth having needed snookers.
On the other table, Kyren Wilson leads 5-4 against Crucible first-timer David Grace.
Both of the best-of-19 matches will play to a finish on Sunday.
O'Sullivan - third favourite behind Judd Trump and Mark Selby to lift the trophy - has been in patchy form this season, reaching four major finals, but claiming just the Masters, albeit for a record seventh time.
He has not won back-to-back matches in any of his past five tournaments since triumphing at Alexandra Palace in January.
During that event, The Rocket spoke about "missing too many easy balls" and this was evident again as he struggled to clinch frames when given an opportunity.
But he made the first century of this year's championship and claimed the sixth frame on a re-spotted black - having needed a snooker - to hold a slender overnight lead.
Wilson, who made a maximum 147 break in qualifying, hit back with consecutive frames late on in the session, as well as the all-important final frame.
He was 63 behind but forced his opponent to foul following well-played snookers, before a composed clearance from green to black.
Meanwhile, Wilson - a beaten finalist in this season's Indian Open - stroked in a top break of 72, but breaks of 75 and 56 allowed Yorkshireman Grace to stay in touch.