Mark Selby was in Crucible turmoil after slumping 7-2 behind against Joe Perry in his Betfred World Championship opener on Saturday.
The defending champion was out of sorts and needed a drastic improvement in the evening session to keep alive his hopes of a fourth world title in five years.
In a best-of-19-frame contest, a player can start slowly and build momentum, but there was little to indicate Selby would turn this around.
The Leicester cueman spoke on Friday of the need to ensure any bad sessions in long matches are not too painful, and typically limiting the damage is one of his great strengths.
When he pulled back from 4-0 to 4-2 against Perry with breaks of 74 and 92, a familiar Selby recovery looked to be well under way.
It was soon checked, though, by 43-year-old Perry, a former semi-finalist in Sheffield, who rattled in breaks of 59, 84 and 109 to cream off three frames in a row and reassert his dominance.
Perry battled through three qualifiers to reach the main draw and the Cambridgeshire cueman was clearly match sharp, unlike recent China Open winner Selby who has scarcely given such a flat performance at the Crucible.
Since the theatre became the home of the World Championship in 1977, six defending champions have lost in the first round. Stuart Bingham is the most recent to have suffered that fate, losing in 2016 to Ali Carter in his opener.
On the other table, Hong Kong's Marco Fu fell 6-3 behind against 20-year-old Chinese debutant Lyu Haotian, who made breaks of 122 and 127 on an assured first appearance.