Baker goal not enough for Blues
Pompey suffered their first home defeat of the season despite a spirited fightback against Doncaster.
The visitors took advantage of their slow start to cruise into a two-goal lead, courtesy of strikes from John Marquis and Andy Williams.
But Carl Baker reduced the arrears before the interval and the Blues poured forward after it in search of a leveller.
They hit the woodwork and had another effort cleared from the line, but were unable to make another breakthrough.
Paul Cook made one change from the side beaten at Blackpool earlier in the week.
That came at the back, where Tom Davies dropped to the bench to make way for Matt Clarke.
Pompey looked to make a fast start, but Gary Roberts strayed narrowly offside when Conor Chaplin tried to send him through on goal.
Instead they fall behind on seven minutes after David Forde came tearing out of his area to mop up a long ball over the top.
It was former Blues loanee Marquis who got their first, however, taking the ball past the keeper and then slotting it into an empty net.
They might have doubled their advantage soon after, but Williams mis-cued his effort and Forde made a comfortable save.
Baker then went close at the other end, drawing a stop from Marko Marosi, despite being surrounded by three defenders the moment he was teed-up by Enda Stevens
And Chaplin wasted a decent opportunity by scuffing his shot after Kal Naismith had expertly brought the ball down on the edge of the box.
Pompey were looking sloppy, however, and guilty of gifting Doncaster possession on far too many occasions.
They fell further behind on 34 minutes, with Williams afforded to space to collect a deep free-kick, swivel and find the net.
The hosts finally clicked into gear towards the end of the first half and thought they should have won a penalty.
Gareth Evans went down in the box under pressure from Tommy Rowe, but referee Darren Deadman decided he had dived and brandished a yellow card, much to the chagrin of Pompey’s right-back.
Baker almost reduced the deficit on 38 minutes with a fierce 30-yard strike that was superbly tipped over by Marosi.
A low Roberts cross was then almost turned into his own net by Cedric Evina and the left-back must have breathed a sigh of relief when he saw the ball instead go behind for a corner.
But Pompey finally made a breakthrough just before the interval, although they did receive a slice of good fortune.
Evans’ cross appeared to be going behind, but Jordan Houghton inexplicably kept it in play, laying the ball on a plate for BAKER to emphatically fire into the roof of the net.
Half Time: Pompey 1 Doncaster 2
Chaplin started an attack when he stole the ball from Matty Blair and launched a quick counter-attack after the restart.
He then fed Roberts’ down the left, but the midfielder’s return pass to the far post was headed to safety.
It was then Doncaster’s turn to threaten, with Michael Doyle intercepting Marquis’ cross before the striker bent another effort narrowly wide.
Cook made a double switch on 54 minutes, with Naismith and Danny Rose making way for Milan Lalkovic and Amine Linganzi.
Rovers were still in the ascendency, though, and Doyle made a crucial block after Williams had skipped past a couple of challenges.
But Chaplin had an excellent opportunity to equalise just past the hour mark. He was picked out unmarked in the box by Roberts, but had to adjust his body and was unable to divert the ball on target.
Christian Burgess then headed wide from close range following another excellent delivery from Roberts.
Cook made his final throw of the dice on 71 minutes, with Curtis Main given a chance to impress against his former side in place of Chaplin.
It was Baker who almost levelled moments late, though, when he diverted Lalkovic’s shot against the crossbar.
And Main was then unable to beat Marosi from point-blank range after Evans’ cross had been turned back into the centre by Roberts.
Rovers soon had a chance at the other end when Clarke mis-hit the ball, but Forde came to the rescue with a smart save.
But it was largely one-way traffic and Pompey thought they had found an equaliser on 81 minutes.
Roberts met Baker’s cross with a firm header, only for it to be hacked clear by Andy Butler, despite blue-shirted appeals that the ball had crossed the line.
The display of six additional minutes provided some hope for the Fratton faithful, but the Blues were unable to salvage a point.
Pompey (4-2-3-1): Forde; Evans, Burgess, Clarke, Stevens; Rose (Linganzi 54), Doyle (c); Baker, Roberts, Naismith (Lalkovic 54); Chaplin (Main 71)
Goals: Baker 42
Subs not used: O’Brien, T.Davies, Bennett, Smith
Doncaster (4-1-2-1-2): Marosi; Richardson (Calder 29 (Mason 69)), Wright, Butler, Evina; Houghton; Blair, Rowe; Coppinger (c) (Middleton 76); Marquis, Williams
Goals: Marquis 7, Williams 34
Booked: Butler, Evina, Marquis
Subs not used: Etheridge, Baudry, Mandeville, Beestin
Referee: Darren Deadman
Attendance: 16,950 (449 away fans)