Millwall captain Jake Cooper’s attempted clearance ricocheted off Waddingham and into the back of the net in the 82nd minute to settle an error-strewn Championship contest.

Jenson Metcalfe had put the visitors ahead early on after a mistake from Pompey goalkeeper Nicolas Schmid but it was quickly cancelled out by Lyndon Dykes’ own goal.

And Waddingham’s late winner saw John Mousinho’s side record a third win in four matches.

Pompey made four changes to the side that started their midweek draw at Wolves, with Zak Swanson, Marlon Pack, Ryan Kavuma-McQueen and Marko Milovanovic replacing Jayden Meghoma, Rocco Shein, Tyrese Shade and Ebou Adams.

Alex Neil made only the two changes for Millwall as Max Crocombe replaced the injured Filip Marschall in goal and Luke Cundle came in for Mark Sykes, while fit-again striker Mihailo Ivanovic made his first appearance of the campaign off the bench.

Millwall made the brighter start with Metcalfe scoring the game’s opening goal just six minutes in, capitalising on a calamitous pass forward from Pompey goalkeeper Schmid.

A response came just 10 minutes later when Adrian Segecic’s scuffed free-kick deceived Dykes at the near post, forcing the Millwall forward to get the final touch as it nestled into the back of his own net.

An end-to-end first half ended level, but the intensity continued into the second period with both sides desperately trying to battle the wet and windy conditions and each other to take the lead.

Millwall would have reclaimed their lead on the hour mark if not for the heroics of Madiodio Dia, who threw his body on the line on two separate occasions in quick succession to block shots.

Pompey came close to taking the lead in the final 20 minutes when Swanson’s right-footed corner caused chaos in the Millwall box, but nobody in blue was able to poke the ball home.

Soon after Waddingham, in his first appearance since August due to injury, almost made an instant impact off the bench when he got close to getting on the end of Adams’ cross.

The persistence of the striker was rewarded with eight minutes left when Cooper tried to clear from inside his penalty area but the ball hit Waddingham and flew past Crocombe.

Millwall seemed to run out of ideas and were unable to find their way back in the contest as their winless run extended to three games.