Following a winless run that stretches back to December, Kitson and Ward helped ease Pompey's Championship relegation worries.
Liam Lawrence could have put them in front early on at the Keepmoat Stadium on Saturday but his close-range shot was well saved by Gary Woods, whilst the visitors were given a wake-up call when James Coppinger fluffed his lines.
They took full advantage of that when Kitson headed in after Greg Halford had struck the post in the 42nd minute.
Ward doubled Portsmouth's lead with a fine finish 10 minutes later and although they were on the back foot from then on, they defended stoically - despite being reduced to 10 men after Jonathan Hogg was dismissed for a second bookable offence late on.
The win sees Steve Cotterill's men move seven points clear of the drop zone, whilst Doncaster have now lost six of their last seven games in all competitions.
The hosts conceded a last-gasp goal in a 1-0 defeat at Millwall and manager Sean O'Driscoll made two changes to their line-up with Coppinger and Matthew Kilgallon coming in for Ryan Mason and Steve Brooker respectively.
Their opponents, by contrast, relied on a 90th-minute David Nugent strike to grab a 1-1 draw against Derby and they were forced into making one change, with Ricardo Rocha replacing Aaron Mokoena, who was stranded in South Africa because of work permit issues.
The visitors showed no signs of missing their captain though and they had first sight at goal.
Herman Hreidarsson's strike was deflected into the path of Lawrence, however, the acting Pompey skipper's shot was smothered by Rovers goalkeeper Woods.
At the other end, Sam Hird's half-volley from 25 yards went narrowly wide before Coppinger spurned a golden chance to break the deadlock.
After cutting in from the left and shaking off the challenge of two Pompey defenders, the midfielder found himself off-balance and his tame shot was parried by Jamie Ashdown.
His miss proved costly as Kitson gave Cotterill's men the lead three minutes before half-time.
Hogg's hooked cross was only cleared to Halford on the edge of the area and although his miscued strike came back off the post, Kitson followed up to head in the rebound.
If there was an element of luck to the breakthrough, there was nothing fortunate about the second.
Ward latched on to Nugent's flick-on before sublimely lifting the ball over a helpless Woods in the 52nd minute.
To their credit, Doncaster were the aggressors for the rest of the match, with Portsmouth relying on the odd counter-attack.
However, chances were at a premium for the hosts and John Oster's strike from 20 yards, which was comfortably saved by Ashdown, was the closest they came to halving the deficit.
Portsmouth did not have things all their own way though as Hogg picked up a second yellow card for deliberate handball in the last minute of normal time.
It mattered little though, as they had already wrapped up the win by then.