Pompey 1 Peterborough 0
Miles Storey netted his first Pompey goal as Peterborough were victims of a Capital One Cup upset at Fratton Park.
The on-loan striker confidently arrowed home early in the game to dump out the League One outfit.
It was an assured display from the Blues, who dominated the first half and were not put under too much pressure in the second.
Andy Awford made six changes from the side that drew at Exeter on the opening day of the season.
Paul Robinson and Alex Wynter were both handed debuts, while there were also starts for Joe Devera, Dan Butler, Nigel Atangana and Storey.
It was the League Two side who looked the more lively early on and Craig Westcarr was inches away from meeting Danny Hollands’ cross.
The striker then brought down a long punt forward, but Michael Bostwick was able to clear the danger.
Atangana was next to go close, although he could only fire the ball straight into the arms of Posh keeper Ben Alnwick.
Pompey were able to make their pressure count on 12 minutes, though.
Butler and Westcarr combined well to tee-up STOREY, who sent a super low strike into the bottom corner.
That failed to sate the hosts’ attacking appetite, with Wynter looking particularly threatening down the right.
Atangana met his cross and saw a shot blocked by Ricardo Santos, before another ball was headed goalwards by Hollands and plucked out of the air by Alnwick.
The rest of the half passed by without too much incident, although it was still the Blues looking the more dangerous as Paul Jones was a virtual spectator.
Half Time: Pompey 1 Peterborough 0
Peterborough looked more of a threat after the restart and skipper Jack Payne soon tested Jones’ handling with a powerful effort from the edge of the box.
Kgosi Ntlhe then had the ball in the net on 55 minutes, only to be denied by the linesman’s flag.
But Pompey were looking pretty comfortable at the back as they dealt with whatever their higher level opponents could throw at the them.
Awford was forced into a couple of changes, though, as Storey and Wynter limped off to be replaced by Ryan Bird and Adam Webster.
Westcarr thought he had doubled the Blues’ advantage on 71 minutes after stealing possession and sliding past Alnwick, but referee Brendan Malone had spotted a handball.
At the other end, Devera was forced to head the ball over his own crossbar as the Posh tried to find a leveller.
Jed Wallace then came on for Westcarr as Awford made his final throw of the dice on 75 minutes.
But the closing stages were not too nerve-wracking for the Fratton faithful as Pompey comfortably booked their place in the second round.
Pompey (3-5-2): Jones; Devera, Robinson, Chorley (c); Wynter (Webster 60), Atangana, Dunne, Hollands, Butler; Westcarr (Wallace 75), Storey (Bird 58)
Goals: Storey 12
Subs not used: Bass, Ertl, Awford, Maloney
Peterborough (4-4-2): Alnwick; Smith, Bostwick, Santos (McCann 78), Ntlhe; McEvoy, Payne (c) (Ferdinand 83), Anderson, Mendez-Laing; Washington, Vassell (Barnett 65)
Subs not used: Olejnik, Brisley, Conlon, Luto
Referee: Brendan Malone
Attendance: 7,726 (384 away fans)