Ryan Day of Wales took a comfortable 6-2 lead over China's Cao Yupeng in the first session of their last-16 match at the world snooker championship on Friday.
Cao, a Crucible debutant, had several clear chances but missed some crucial shots which allowed Welshman to build up a commanding lead under the best of 25 frames.
The 21-year-old rookie is the only Chinese player advancing to the last 16 after his compatriot Ding Junhui was upset by Ryan 10- 9 in the first round.
With four frame advantage, the 32-year-old Welshman will go into their second session tomorrow morning with confidence.
Australian Neil Robertson became the first to reach the quarterfinals so far after his 13-9 victory over David Gilbert tonight.
The 2010 world champion seemed promising to win his second Crucible title after his two-round strong performances. He will meet Ronnie O'Sullivan or Mark Williams in the last eight.
Stephen Maguire moved closer to the quarterfinals after he won six of the eight frames in the second session against Joe Perry, consolidating a 11-5 lead.
The world No. 7 needs just two more frames Saturday morning to secure a last-eight berth against Stephen Hendry or John Higgins.
Seven-time "Crucible King" Hendry just stood on the brink of fending off the defending champion John Higgins as he led 12-4 after his second session.
Four-time world champion Higgins now looked certain to fail in his bid to retain the title in front of the in-form 43-year-old veteran.
Hendry only needs one frame to book an 18th quarterfinal appearance in Sheffield in the final session on Saturday.