Pompey trail 2-1 at the break at Southend.
The Shrimpers opened the scoring on six minutes when Matt Clarke inadvertently put the ball into the back of his own net, before Jason Demetriou doubled the hosts' advantage in the 12th minute.
Gareth Evans grabbed a goal back for the Blues nine minutes before the break.
Here's Pompey's match ratings from the first half...
Luke McGee - Helpless for both goals 6
Anton Walkes - Caught dwelling on the ball for Southend's first goal 5
Christian Burgess - Made a few good challenges and clearances 6
Matt Clarke - Had to make the challenge on Harrison that led to his own goal 6
Dion Donohue - Left Stephen McLaughlin unmarked, which allowed the Southend winger to tee up Demetriou for Southend's second 5
Gareth Evans* - Put his body on the line for goal before being substituted 6
Nathan Thompson - Quick at closing down and made several good blocks 6
Ben Close - Passing radar way off at times 5
Jamal Lowe - Fantastic run that led to Evans' goal 6
Conor Chaplin - Should have scored in the first minute, but has been busy enough 6
Brett Pitman - Intelligent cut-back for Evans' goal 6