Matthew Stevens finally started to show his trademark fluency as he drew level at 10-10 with rank outsider Graeme Dott for only the second time in their Embassy World Championship semi-final at the Crucible.
Stevens has struggled to demonstrate his best form against a player who needs to reach the final to maintain his place in the top 16 for the 2004-2005 campaign.
Dott began the third session impressively with a break of 61 to the final yellow which extended his advantage to 10-7.
The Scot looked full of confidence, but errors began to creep into his play and 2000 finalist Stevens took full advantage.
Dott broke off in frame 18 and left Stevens a red into the black pocket which he sank to set him on the way to a fine 104 - his second century of the best of 33 match.
In the next Dott made a mess of an attempted safety shot with reds scattered all over the table and Stevens again took full toll with a run of 84.
Stevens looked to be growing in belief and he went into the interval all square with the help of 52 in frame 20.
The duo had shared the eight frames in the morning session when Dott had the distinction of registering the 50th century of this year's championships with a 117 giving him his first ton of the 2004 finals.
Dott had moved 8-5 clear at one stage and Stevens was relieved when he left the final black hanging over the pocket in frame 14 before they shared the final two of the session.