Pett's early goal the difference
Gary Waddock’s first match in caretaker charge of Pompey ended in a narrow defeat at Stevenage.
Tom Pett’s early goal proved the difference between the sides, as the hosts continued their play-off charge.
The Blues were poor before the break, but created plenty after it and substitute Craig Westcarr had a leveller ruled out for offside.
Waddock made three changes from the side beaten at Morecambe on Saturday and reverted to a 4-4-2 formation.
Nicky Shorey was handed a first appearance for more than two months at left-back, while there were also returns for Adam Webster and Danny Hollands.
Wes Fogden dropped to the bench, but Jed Wallace (hamstring) and Josh Passley (head) both missed out through injury.
It might have been a new chapter for Pompey, but there was a familiar start to proceedings as they feel behind early on.
A deep free-kick was only cleared as far as Pett on the edge of the box and the midfielder drove the ball past Paul Jones’ grasp and into the bottom corner.
The visitors were not creating much, although Matt Tubbs forced a routine save from Boro keeper Chris Day after meeting a Ryan Taylor cross.
Taylor’s evening came to a premature end on 27 minutes, though, when he picked up a groin injury and was replaced by Westcarr.
Stevenage were not being put under too much pressure, but a drive from Nigel Atanagana caught a huge deflection off Jerome Okimo and looped into Day’s arms.
Webster’s strong header was then laid off by Tubbs and Westcarr’s shot was bravely blocked by skipper Bira Dembele.
Pompey were not being overly troubled at other end, but the hosts did come close to doubling their advantage in stoppage-time.
Dembele met Simon Walton’s corner with a volley that bounced into the turf and landed on the roof of the net.
Half Time: Stevenage 1 Pompey 0
The Blues came close to getting back on level terms early in the second half when Westcarr found Dan Butler in space.
The left-back bore down on goal, but despite getting plenty of power behind his strike, could not beat Day at the keeper’s near post.
Atangana then sent Westcarr clear through moments later, only for linesman Thomas Ramsey to belatedly raise his flag for offside.
Pompey were looking a lot stronger than before the break and a Butler free-kick from the left caused problems in the Boro box on 57 minutes before Dembele was able to head clear.
James Dunne was particularly keen to grab the game by the scruff of its neck as he looked to impress against his former side.
The hosts appeared short on inspiration, but Chris Whelpdale suddenly threatened twice in as many minutes midway through the second half.
First his shot took a massive deflection off Webster and looped narrowly over before, after being found in acres of space, he hit a tame effort straight at Jones.
It looked like Pompey had levelled on 70 minutes, though, with a move that started with a fine pass from Webster.
He picked out Butler down the left and the defender’s low cross was deftly flicked home by Westcarr, only for his celebrations to be cut short by the linesman’s flag.
Waddock immediately made his second switch, with Tubbs making way for Paul McCallum in the Blues’ front-line.
There was a strange moment on 81 minutes when Pompey won a free-kick and Butler, unhappy with the Stevenage wall, paced out the 10 yards himself.
Referee Christopher Sarginson, however, did not see the funny side and, rather harshly, showed the full-back a yellow card.
Fogden replaced Atangana for the closing stages and the Blues kept pushing forward in search of a point, but the hosts held firm to claim the spoils.
Stevenage (4-2-3-1): Day; Bond, Wells, Dembele (c), Okimo; Walton (Lee 58), Conlon (Keane 58); Whepdale, Parrett, Pett; Beardsley (Andrade 82)
Goals: Pett 3
Booked: Walton, Wells, Lee
Subs not used: Beasant, Henry, Worley, Akinyemi
Pompey (4-4-2): Jones; Devera, Nosworthy, Webster, Shorey; Atangana (Fogden 82), Dunne, Hollands (c), Butler; Tubbs (McCallum 70), Taylor (Westcarr 27)
Booked: Devera, Butler
Subs not used: Poke, Ertl, Close, Chaplin
Referee: Christopher Sarginson
Attendance: 3,615 (703 Pompey fans)