Rovers showed incredible resolve under tremendous pressure to hold on for a superb win over Portsmouth at Fratton Park.
Goals from John Marquis and Andy Williams gave Rovers the advantage as they showed a welcome ruthless streak against a side that had won their previous four games on home soil.
But a mistake allowed Carl Baker to reduce the deficit for the hosts before the break and gave Pompey a way back into the game.
Portsmouth piled on the pressure in search of an equaliser but met a resolute Rovers defence that refused to give an inch.
It was an effort that deserved to reap rewards with bodies thrown in front of shots and heads stuck in dangerous players to ensure Pompey did not breach them again.
Ferguson made one change from the side that drew against Carlisle United in midweek with Frazer Richardson restored to right back and Riccardo Calder dropping to the bench.
Full back Enda Stevens was the only starter of Portsmouth's ex-Rovers contingent with Curtis Main, Kyle Bennett and Milan Lalkovic all on the bench.
Rovers started superbly, pressing well and finding gaps between Portsmouth's two banks of midfielders with neat, intricate passing.
But it was an opportunistic run that gave them the opening goal on seven minutes.
Andy Butler sent a clearance forward which Marquis chased, latching on and knocking the ball past on-rushing Pompey keeper David Forde before slotting into an empty net from 15 yards.
Williams sliced a volley to Forde after Butler's header across goal took an age to drop before Marko Marosi made a fine save at the other end on 18 minutes as Portsmouth threatened for the first time.
Stevens' low cross was collected by Carl Baker who worked space for a rasping drive which Marosi parried away superbly.
It began a strong period of pressure from the hosts as they began to find their feet in the game.
But Rovers defended resolutely and bravely, cutting out a plethora of crosses as Portsmouth pushed towards goal.
Pompey struggled to threaten Marosi with Conor Chaplin scuffing a shot from the edge of the box after finding space while Joe Wright cut out a searching cross with Gary Roberts poised to strike.
Rovers were forced into a change on 28 minutes when Richardson suffered a knock, with Riccardo Calder coming off the bench.
But six minutes later they doubled their advantage.
Butler flicked on a long ball from Wright and Williams watched it loop over his shoulder before poking past Forde from close range.
The hosts continued to look the more threatening and had a big claim for a penalty when Gareth Evans tumbled after a tackle from Tommy Rowe but the Portsmouth full back was booked for diving.
Marosi produced a stunning save to keep Rovers' advantage at two eight minutes before the break.
Carl Baker smashed a shot from 25 yards that looked destined for the top corner until Marosi palmed it away.
After plenty of resolute defending it was a mistake from Wright which finally saw the hosts get off the mark three minutes before the break.
Marosi left Evans' cross as it appeared to be heading out for a goal kick but Wright attempted to hook the ball away only to send it straight to Baker who smashed into the top corner from 12 yards.
Portsmouth, as expected, remained on the front foot as the second half began.
But Rovers threatened on the counterattack with some incisive breaks and should really have increased their advantage.
Marquis curled just wide from one such break after being fed into the box by Coppinger.
And Williams arguably should have made it three for Rovers from another as he worked space for a shot but struck a tame effort which was easily cleared.
Rovers became a little nervy in defence as the pressure mounted.
Former Rovers loanee Milan Lalkovic should have equalised for the hosts. Roberts' deep flashed cross flew over everyone but Lalkovic could only head it back from where it came with the goal gaping.
Ferguson looked to stem the Portsmouth pressure by substituting a substitute, taking off Calder for Niall Mason, who went to right back.
But the hosts hit the bar soon after as Baker got a touch on Lalkovic's shot from distance and looped it onto the top of the woodwork.
Marosi had to be alert to scoop up Roberts' low cross with ex-Rovers striker Main lurking at close range.
Rovers could still only threaten on the break but should have been 3-1 up 13 minutes from time.
Williams charged onto a long ball with Forde rushing out of his goal. The pass was on to Marquis who had an open goal ahead of him but Williams opted to shoot himself and the effort was blocked.
It made for a nervy finish to the game from a Rovers perspective.
And there were no more nervy moments than when Butler cleared off the line from Roberts' header.
Rovers switched to a five man defence as full time neared as the piled bodies in the box to hold off the onslaught.
Baker curled a free kick over the bar and Matt Clarke headed just wide from a corner as Portsmouth pushed.
But they could not find the opening as Rovers held on for an important three points.
Portsmouth: Forde, Evans, Clarke, Burgess, Stevens, Doyle, Rose (Linganzi 54), Baker, Roberts, Naismith (Lalkovic 55), Chaplin (Main 71). Subs not used: O'Brien, Davies, Smith, Main, Bennett.
Rovers: Marosi, Richardson (Calder 29, Mason 68), Wright, Butler, Evina, Houghton, Blair, Rowe, Coppinger (Middleton 75), Marquis, Williams. Subs not used: Etheridge, Baudry, Beestin, Mandeville.
Referee: Darren Deadman (Cambridgeshire)
Attendance: 16,950 (449 away)