Limp Pompey succumbed to defeat at a rain-sodden Ewood Park this afternoon.
Blackburn claimed a 3-0 victory amid the puddles, an outcome thoroughly deserved.
Kenny Jackett’s men never got going on their second northern trip within four days and were easily second best.
The nearest they came to netting was a first-half volley from Kyle Bennett from Jamal Lowe’s cross, saved by David Raya in a rare goal attempt.
Meanwhile, Rovers made light of atrocious weather conditions and, although it took until the 38th minute to break the deadlock, they had long been in charge.
That moment arrived when Dion Donohue was dispossessed near the half-way line by Harry Chapman and the loanee charged forward before feeding Bradley Dack for a powerful finish.
The match was effectively sealed on 58 minutes through excellent work from Derrick Williams.
The left-back charged down flank and fed the ball inside for Danny Graham to finish with a crisp right-foot shot into the bottom corner.
Rovers were reduced to 10-men when substitute Dominic Samuels kicked out at Christian Burgess in the 87th minute,
Then in the 90th minute, with defenders slipping over, substitute Craig Conway took advantage to claim the loose ball and clip it over the advancing McGee.
And it represented successive away defeats for Jackett’s men with another disappointing showing on their travels.