Grant McCann's second spell in charge of Peterborough United began with defeat by his former club Hull City as Posh sank to the foot of the Championship.
McCann, dismissed by new Tigers owner Acun Ilicali last month, saw his new side fall to a fifth loss in six matches as relegation looks increasingly likely.
Keane Lewis-Potter's stunning double sealed the points for Hull after Tyler Smith had opened the scoring with his first league goal.
Victory lifted Hull to 18th in the table, 14 points clear of the bottom three, with Peterborough remaining eight points from safety.