Trailing at half-time to Yuki Ohashi’s opener, John Mousinho’s men levelled on 62 minutes through Callum Lang’s first of the season, finishing off Josh Murphy’s cross.
Then, 11 minutes from time, Conor Chaplin’s right-wing corner was headed home by Bowat to secure a 2-1 triumph.
It was a priceless win for the Blues, lifting them into 21st - a point outside the relegation zone - and here are our player ratings…
1. Ibane Bowat heads home Pompey's winner
Ibane Bowat celebrates after heading home Pompey's winner against Blackburn. Picture: Graham Hunt/ProSportsImages Photo: Graham Hunt
2. Nicolas Schmid - 7
Couldn’t do anything about Ohashi’s goal on the counter attacker and had little to do in terms of saves. But commanded his area well and took everything cleanly which came his way. Photo: Graham Hunt
3. Terry Devlin - 8
Strong first half, despite being beaten by Ohashi for the goal on the counter attack. Made a real niche for himself at right-back now and going to be extremely hard to dislodge amid fierce competition. Great late tackle on Gueye. Photo: Graham Hunt
4. Hayden Matthews - 8
(Replaced by Jordan Williams on 90 mins) Demonstrated a lot more aggression to his game and he put in his best performance of the season. Strong in the air, confident in possession and keen to drive forward. This was the Hayden Matthews of last term. Photo: Graham Hunt