Jason Roberts recovered from a bout of swine flu to leave Portsmouth feeling sick themselves at Ewood Park as Blackburn Rovers came from behind to claim three priceless Barclays Premier League points.
Rovers had been reeling at the end of a poor first period in which Jamie O'Hara fired the visitors ahead with a 30-yard strike past Paul Robinson in the 15th minute.
But Roberts clambered off the bench at the break to steer a 52nd-minute leveller past David James - and added Rovers' third after Ryan Nelsen had netted a rare goal to put his side in front.
The win brought sighs of relief all round for the home side - and especially manager Sam Allardyce, whose half-time changes were vindicated.
With Roberts forming a multi-purpose strikeforce along with Franco Di Santo and fellow substitute Benni McCarthy, Rovers ultimately did enough to wriggle clear of the relegation zone.
For Pompey, however, the late drama provided a jolt back down to earth following their emphatic 4-0 win over Wigan Athletic last week - which hinted their appalling start might have been a thing of the past.
out-jumping
Rovers started best in their bid to exit the drop-zone, a Pascal Chimbonda shot causing chaos in the Pompey box and almost presenting a chance for El-Hadji Diouf.
In a low-key opening, Younes Kaboul and O'Hara's low shots dribbled wide for the visitors - while Anthony Vanden Borre missing a half-chance after being fed in the box by Kevin Prince-Boateng.
But Pompey's lead came out of nowhere when Aruna Dindane fed O'Hara in centre field, and the latter found a way past Robinson with a low left-foot shot from 30 yards.
Rovers were offering next to nothing in response, and frustration grew among the home fans as Marc Wilson came close to making it two by out-jumping the home defenders for an O'Hara free-kick.
Diouf got behind the Pompey defence on the half-hour only to be let down by a poor final ball which was cleared by Kaboul, as the visitors' rearguard held firm.
Rovers' woes were summed up in the 33rd minute when, having won a free-kick 30 yards from goal, the recalled Morten Gamst Pedersen lofted a set-piece attempt high and wide.
At half-time, Allardyce had no choice but to ring the changes - introducing Roberts and McCarthy in place of Diouf and Pedersen.
paid dividends
The hosts finally managed their first shot on target in the 48th minute when Pascal Chimbonda played the ball out to Dunn - whose effort from a tight angle was easily held by David James.
But Pompey came close to grabbing a second in the 50th minute when O'Hara curled in a free-kick from the left and Kaboul rose to glance his header just wide of target.
Allardyce's double change paid dividends when Nelsen headed down Dunn's corner in the box, and Roberts reacted quickest to steer the equaliser past James.
Roberts almost squeezed between Wilson and Tal Ben Haim to get a foot to a McCarthy pass in front of goal - but O'Hara remained a danger and hit another long-range effort into Robinson's arms.
Nelsen's superb 73rd-minute header from Dunn's corner put the home side in front in what was only the second goal scored by the New Zealand captain in almost five years at the club.
Roberts wrapped up the points five minutes from time when he stole into the box to put the finishing touches to a left-wing cross from McCarthy.
