Liam Mandeville marked his return to the starting line-up with his first goal of the season to set Rovers on the way to their second home win in the league of the season.
He scored in a quick fire opening, followed by a Tommy Rowe effort, which set Rovers on the way to victory.
Manager Darren Ferguson made four changes from the side that lost 1-0 at Charlton Athletic on Saturday.
Defender Mathieu Baudry was the most notable newcomer into the Rovers’ side, making his first appearance of the season following his injury over the summer.
Rovers made a bright start at the Keepmoat Stadium, and were a goal up inside the opening three minutes of the game.
Rowe collected the ball near the half-way line and danced his way through the Pompey defence, sliding the ball across for Rodney Kongolo inside the area.
Kongolo swept the ball across goal for Mandeville to smash home past Luke McGee in the visitors’ goal and hand the home side an early lead.
A good start was made even better less than two minutes later as Rovers doubled their advantage against last season’s Sky Bet League Two champions.
Harry Toffolo’s corner from the left was swung in and met by the on-rushing Tommy Rowe at the far post.
His powerful header landed in the back of the net, via a slight deflection from Matt Clarke to give Rovers a two-goal advantage inside the game’s opening five minutes.
Pompey were left shocked by the start to the game, and from another Toffolo corner, it was almost three.
Toffolo’s second corner from the left was this time met by Andy Butler, but his header was blocked by team-mate Joe Wright when it looked destined for the bottom corner.
It was a brilliant opening 10 minutes for Rovers, and a shell-shocked Pompey tried their best to get back into the game straight away.
Gareth Evans cross into the box was headed back into the middle by Oliver Hawkins, but former Rovers man Kyle Bennett couldn’t keep his shot down from six yards out and fired well over.
The visitors’ next chance came from yet another ball into the box, this time a free-kick over on the left from Matty Kennedy was met by Christian Burgess.
Burgess’ header looped over Ian Lawlor in the home goal, but Wright was there to make a goal-line clearance, this time in front of his own goal, to ensure that Rovers two-goal lead remained intact.
Portsmouth started to grow into the game, after a fast start from Rovers, and their next chance came from yet another ball into the box from Kennedy.
Kennedy’s initial ball in was cleared away but only to Nathan Thompson who fed the ball across to Ben Close, but his half-volley was blocked well by Ben Whiteman and Rovers saw out the danger.
Rovers closed the half out well however, maintaining much of the possession and forcing Pompey to remain within their own half, and went into the break good value for their two-goal lead.
The visitors came out fired up after the interval, and went very close to pulling a goal back in the first five minutes of the second half.
Jordan Houghton conceded a free-kick on the edge of the area, and up stepped substitute Conor Chaplin, who struck the outside of the post from the resulting set-piece.
Pompey did get their goal not long afterwards, but it wasn’t through their own doing that they did pull one back.
An easy pass back from Baudry wasn’t controlled at all well by Lawlor and the ball trickled just over the line, despite the best attempts of the Irishman to punt the ball away from the Rovers’ goal.
The visitors were doing all they could to get back into the game, and could’ve had an equaliser 10 minutes later.
A corner from Kennedy was cleared out by the Rovers defence but only out as far as Dion Donohue on the left-hand side, and his cross was met by Chaplin, but he could only clip his effort wide of the near post.
Donohue’s night wouldn’t continue for much longer however, with the Pompey man lashing out at Niall Mason after a failed attempt to get around the defender, leaving the referee with no option but to send him off.
Kongolo tried his best to extend the Rovers’ lead once again as the clock ticked towards 90 minutes, winning the ball back from Kennedy and charging down on goal, however his shot was deflected behind by the man he dispossessed.
In dramatic fashion, Pompey had one last chance to equalise, with Kennedy again causing a problem down the left for the Rovers’ defence.
His ball into the box was met by the unmarked Jamal Lowe, who’s header looked destined for the corner, but Lawlor made a superb save to his left to save all three points for Rovers in added time.
This secured back-to-back home wins for Rovers, who will now host Walsall on Saturday in a bid to get yet another three points at the Keepmoat Stadium.
Make sure you are at the Keepmoat Stadium on Saturday by getting your ticket from our Box Office by calling in at the ground, calling 01302 762576 or going to tickets.clubdoncaster.co.uk.