Mark Williams won his third world snooker title in May 2018Betfred World Snooker ChampionshipVenue: Crucible Theatre, Sheffield Dates: 20 April-6 MayCoverage: Watch live on BBC One, BBC Two, Red Button, iPlayer, Connected TV, BBC Sport website and BBC Sport app.
Champion Mark Williams won five frames in a row on his way to building a 6-3 lead over qualifier Martin Gould in the first round of the World Championship.
Former world number 11 Gould took the opener, but missed chances in all the following three frames and trailed 3-1.
Welshman Williams, 44, hit his second half-century, followed by a stylish 129 for a 5-1 advantage.
England's Gould took the next two frames but a 97 gave Williams the upper hand in the best-of-19-frame tie.
In the other morning match, number 14 seed Luca Brecel battled back from 3-2 down to lead Englishman Gary Wilson 5-4 at the end of their first session.
Williams and Gould play to a finish on Saturday evening, when Scotland's number 15 seed Stephen Maguire begins his tournament against Tian Pengfei, one of six Chinese players appearing at the Crucible this year.
The afternoon play sees 2010 champion Neil Robertson take on qualifier Michael Georgiou, who is one of seven debutants.
Chinese superstar Ding Junhui also begins his latest quest for a first Crucible title against world number 24 Anthony McGill.
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