World number one Mark Selby has a slender 5-4 advantage after the first session of the best-of-19 China Open final against Mark Williams.
Three of the opening four frames contained century breaks and English world champion Selby went 3-1 ahead.
Williams, needing to win the title to return to the top 16 and qualify automatically for this month’s World Championship, cut the deficit to 4-3.
And the Welshman won the final frame of the session with a break of 106.
Defeat for 42-year-old Williams, a two-time world champion, would mean he would have to win three best-of-19-frame preliminary matches in the qualifying tournament at Ponds Forge in Sheffield from 5-12 April to earn a place in the 32-man draw for the Crucible.
Selby, 33, moved 2-0 ahead with a break of 100, but Williams responded with a 124 in the next frame.
Williams, who has not won a ranking title since the 2011 German Masters – when he beat Selby in the final – potted a red in the fourth but touched the brown in doing so and Selby replied with a break of 109.
The remaining frames were more scrappy but left-hander Williams, three times a winner of the China Open, remained in contention into the final session with his second century of the match.
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