Dion Donohue netted his first Pompey goal to secure victory at Crawley in an uneventful Checkatrade Trophy contest at Broadfield Stadium.
But the result was enough to ensure that the Blues have reached the knockout stages with a group game to spare.
There was not a lot for either goalkeeper to do on a mild evening in Sussex and Donohue’s effort was comfortably enough to secure all three points.
Joe Mason could even afford to miss a late penalty in a game that will not live long in the memory of anyone present – bar Donohue, perhaps.
Kenny Jackett made nine changes from the side that finally suffered a league defeat to Gillingham at the weekend.
Gareth Evans – who wore the captain’s armband – and Ben Close were the only players to keep their places.
There were debuts for Louis Dennis and 16-year-old academy full-back Haji Mnoga, while a fit-again Donohue made his first appearance of the season.
Meanwhile, another member of Pompey’s youth set-up, midfielder Freddie Read, was an unused substitute.
Both sides took a while to grow into the game, with clear-cut chances at a premium at both ends throughout the first half.
A shot from Tarryn Allarakhia flew straight at Luke McGee, while the keeper also dealt with David Sesay’s deflected drive.
Then when a George Francomb delivery was only partially cleared, Panutche Camara and Dannie Bulman both had efforts blocked in quick succession.
There were a few crosses for Crawley to deal with at the other end of the pitch, but nothing that the visitors could capitalise on
Dennis did try his luck from the edge of the box, although the ball flew harmlessly wide of Yusuf Mersin’s post.
There was a scare when Evans lost possession inside his own area, although the skipper did well to win it back.
And Pompey went straight up the other end to break the deadlock, with Mason feeding DONOHUE, who cut in from the left and arrowed home a neat finish.
Crawley Town 0
Jackett replaced Evans with Matt Clarke at the start of the second half, as he matched the hosts by playing with three at the back.
But the Reds should have been level soon after the restart, with Sesay doing the hard work by beating Donohue down the right.
He squared for an unmarked Brian Galach, but the striker somehow side-footed his shot wide from 12 yards.
Close was not far away from making him pay for his profligacy, with a trickier attempt that flew narrowly over.
It was still not proving to be a game full of excitement, however, with Pompey content to play some patient passing football.
Josh Doherty had an opening for Crawley when he sent the ball into the danger zone and it evaded everyone to roll inches past the post.
Jackett made his final two changes just past the hour mark, as Mnoga and Donohue were withdrawn for Ben Thompson and Tom Naylor, with the latter slotting into defence.
The visitors tried to make sure of the victory and Close’s shot was gathered by Mersin after Anton Walkes had headed down Clarke’s free-kick.
Thompson’s low centre for Mason was just about intercepted, while Clarke nodded a corner wide as the match wound down.
Allarakhia sent a 25-yard thunderbolt fizzing narrowly wide, as the Reds tried their best to force a draw.
But Mason should really have wrapped things up for Pompey from 12 yards after Walkes had been tripped in the box by Mark Randall.
Referee Tim Robinson pointed straight to the spot, but the striker blazed his penalty high over the bar.
Crawley (3-1-4-2): Mersin; Francomb, McNerney, Vincelot; Bulman (c); Sesay, Allarakhia, Camara (Randall 61), Doherty; Poleon, Galach (Maguire 58)
Booked: Vincelot, Randall
Subs not used: Morris, Young, Connolly, Payne
Pompey (4-2-3-1): McGee; Mnoga (Naylor 65), Burgess, Walkes, Haunstrup; Close, Rose; Evans (c) (Clarke 46), Dennis, Donohue (B.Thompson 64); Mason
Goals: Donohue 37
Subs not used: MacGillivray, Read, Pitman, Hawkins
Referee: Tim Robinson
Attendance: 1,268 (484 Pompey fans)
A disastrous start cost Pompey as they made the long trip home from Doncaster on the back of a 2-1 defeat.
They conceded twice inside the opening five minutes, with Liam Mandeville opening the scoring before Christian Burgess inadvertently turned the ball into his own net.
A comical own-goal from Mathieu Baudry sparked hopes of a comeback, but they were dashed when Dion Donohue – figuratively and literally – saw red.
Kenny Jackett made one change from the side that convincingly beat MK Dons on home soil at the weekend.
Gareth Evans returned to the starting line-up in a wide attacking role on the right and was also handed the captain’s armband.
Jamal Lowe dropped to the bench, having travelled up later than the rest of the squad following the birth of his baby daughter.
Pompey were looking to build on successive league victories, but got off to a terrible start and found themselves two down before some fans had even taken their seat.
They had looked bright immediately following kick-off and a couple of attacks were thwarted by the Rovers back-line.
But the hosts were more clinical and broke the deadlock when Rodney Kongolo collected Tommy Rowe’s pass and squared for Mandeville to prod home.
And Doncaster doubled their advantage a few seconds later, as Burgess inadvertently sliced Harry Toffolo’s corner into his own net.
It almost got even worse for the Blues, but Andy Butler could not guide his header on target after meeting another Toffolo set-piece.
Pompey almost reduced their deficit midway through the first half, with Joe Wright forced to clear from the line when Burgess guided Matty Kennedy’s free-kick towards goal.
That was about it for clear-cut opportunities before the interval, with much of the battle taking place in the centre of the pitch.
Ben Close did see a volley charged down when Kennedy’s cross was headed into his path by Nathan Thompson.
Donohue then lifted a free-kick into the box with the seconds ticking down, but Kennedy was unable to force his shot through a sea of bodies.
Doncaster Rovers 2
Jackett, unsurprisingly, decided to make a couple of changes at the start of the second half, as the visitors looked for a route back into the game.
They were both attacking substitutes, with Evans and Kyle Bennett making for new father Lowe and – making his 100th appearance – Conor Chaplin.
And Chaplin almost made an immediate impression when Oliver Hawkins was fouled right on the edge of the box.
The diminutive striker stepped up take the free-kick and managed to bend it over the wall and against the crossbar.
But the Blues were handed a lifeline in bizarre fashion on 54 minutes – and it is a moment that Ian Lawlor will be keen to forget.
Doncaster’s keeper allowed Baudry’s back-pass to slip under his foot and was unable to hack the ball clear before it crossed the line.
That gave the visitors a visible lift, while their opponents started to display some nerves now their lead was so narrow.
A couple of dangerous Kennedy corners had to be headed clear, while a cross from the winger was then flicked narrowly wide by Chaplin.
But just when the 620 travelling fans started to dream of a comeback, Pompey were suddenly faced with an even steeper mountain to climb.
A frustrated Donohue kicked out at Niall Mason in an off-the-ball incident and although referee Martin Coy missed it, his assistant advised that the left-back should be dismissed.
The visitors kept trying to push forward in search of a leveller, but were obviously now finding it more difficult.
When they did get the ball into dangerous areas, Doncaster had plenty of players back to halt their charge.
There was clearly a bit of needle between the teams and something Mandeville said as he was substituted left Burgess enraged.
But Pompey were almost celebrating deep into stoppage-time when Lowe met Kennedy’s cross, only for his deft header to be superbly kept out by Lawlor.
Doncaster (4-2-3-1): Lawlor; Blair (Mason 46), Wright, Butler (c), Baudry (Beestin 72); Houghton, Whiteman; Kongolo, Rowe, Toffolo; Mandeville (Garratt 88)
Goals: Mandeville 3, Burgess 5 (og)
Subs not used: Marosi, Alcock, Ben Khemis, Fletcher
Pompey (4-2-3-1): McGee; Thompson, Burgess, Clarke, Donohue; Close, O’Keefe; Evans (c) (Lowe 46), Bennett (Chaplin 46), Kennedy; Hawkins
Goals: Baudry 54 (og)
Sent off: Donohue
Booked: Burgess, O’Keefe
Subs not used: Bass, Haunstrup, Oxlade-Chamberlain, Rose, Naismith
Referee: Martin Coy
Attendance: 7,211 (620 Pompey fans)
Transfer : Chesterfield – Portsmouth