Despite an even start, four goals in 19 first-half minutes condemned John Mousinho’s men to a seventh-straight defeat on the road.
The Blues boss had rested five of his players and West Brom gleefully took advantage, albeit Nicolas Schmid gifting them the opening two goals with handling errors.
Thomas Waddingham came off the bench and marked his debut with a goal deep in stoppage time for a rare moment of joy for those travelling supporters as it finished 5-1.
And here are our Pompey player ratings...
9. Conor Chaplin - 9 - MOM
After a 24-game wait in his second Pompey spell, Chaplin opened his account. A lovely first-time left-footed finish from Alli’s pull-back and an emotional goal celebration which clearly meant the world to the attacker. Also set up Adams for his goal and the Blues’ third. He’s one of our own. Photo: Graham Hunt
10. Millenic Alli - 9
(Replaced by Makenzie Kirk on 84 mins) Has been a revelation since his Fratton Park arrival and another strong game. Netted the Blues’ second after sublime Dozzell pass and also created Chaplin’s opener. Strong, direct, pacy and brilliant to watch. And even had a spell up front when Bishop came off injured. Photo: Getty
11. Colby Bishop - 8
(Replaced by Keshi Anderson on 70 mins) A key role in Adams’ goal with a header to the creator Chaplin and again used his physicality to excellent effect. Picked up an injury to left ankle and was forced off. Photo: Graham Hunt
12. Andre Dozzell (21) of Portsmouth on the attack during the EFL Sky Bet Championship match between Portsmouth and West Bromwich Albion at Fratton Park, Portsmouth, UK on 31 January 2026.
Pompey's Andre Dozzell on the attack on against West Brom. Picture: Graham Hunt Photo: Graham Hunt