Goals from Michael Morrison, Jack Storer and Diego Fabbrini sealed the win against former Blues midfielder Mark Cooper's side.
It took Blues only four minutes to register their first attempt. Andy Shinnie curling a 25-yard free-kick over the crossbar, after Koby Arthur was bundled to the ground.
Blues continued on the front-foot and after six minutes created three chances in quick succession.
Jacques Maghoma seeing his effort cleared off the line by defender Ethan Pinnock.
Moments later both Robert Tesche and Jonathan Grounds forced Jonny Maxted into action, firstly thwarting Tesche at his near post, before getting down well to deny Grounds at the resulting corner.
Blues' early dominance paid off as Rowett's side took the lead after 11 minutes.
Maghoma's corner was neatly flicked on by Tesche before finding it's way to the far post where skipper Morrison was on hand to sweep home.
On 20 minutes, the hosts were forced into a change, taking off Drissa Traore - who had taken a knock from Donaldson shortly after the goal - and introducing a familiar face, Darren Carter.
Maghoma again went close; having taken a short corner with Arthur, the winger twisted and turned before seeing his strike canon out off the upright.
The hosts' 'keeper Maxted was again brought into action just before the half hour mark.
After a quick and intricate passing move involving Stephen Gleeson, Maghoma and Shinnie, the latter fired a fierce strike goalwards which Maxted parried straight back into Shinnie's path, but the Scot was unable to keep his second attempt down.
Maxted continued to frustrate the visitors as he then denied Maghoma and Shinnie once more. The Blues winger driving into the Forest Green box, seeing his left-footed effort palmed away by the 'keeper, before Shinnie was again denied, this time by a fine save after he peeled off at the far post from a Tesche free-kick.
On the stroke of half-time, the hosts created their best opportunity by far. The ball found Liam Noble on the edge of the area, bearing down on goal, with only Adam Legzdins to beat, but dragged his effort wide of the post.
Moments later Noble forced Legzdins into his first and only save of the afternoon, the Blues 'keeper getting across his goal well to beat away Noble's free-kick.
Rowett made seven changes at half-time with only Grounds, Gleeson, Arthur and Donaldson re-appearing for the second 45.
After an impressive performance in midweek at Solihull Moors, it didn't take Diego Fabbrini long to get involved. After being on the field for a matter of minutes went close when his effort trickled inches wide of the post.
Just before the hour, the remaining four from the first half made way for Dwight Tiendalli, Luke Maxwell, Reece Brown and Jack Storer.
Blues looked to use the pace of Viv Solomon-Otabor in the second-half and the winger looked lively.
First showing his full-back a clean pair of heels before his cross evaded all at the near post, and then the youngster got clear of his marker once more, checked back onto his right foot, only to see his curling effort from the corner of the area curl narrowly wide.
Blues began to turn the screw and put the hosts under pressure as substitute Jack Storer thought he'd doubled Blues' lead. The striker latching onto a Fabbrini through ball, beating the 'keeper, but not the offside trap.
A minute later Storer stung the palms of the 'keeper as he unleashed a fierce drive from 25-yards, which was beaten behind by the substitute 'keeper.
Reece Brown then saw his low drive fall the wrong side of the post as he could only find the side netting.
After another dominant spell from Blues, they extended their lead through Storer. The striker rising highest to head home Solomon-Otabor's cross, this time with no hint of offside.
With just under five minutes remaining, Paul Caddis nearly got himself on the scoresheet when his block nearly ricocheted into the Forest Green net.
Two minutes from time Fabbrini completed the scoring when he fired across the 'keeper and found far corner.
Forest Green Rovers starting XI: Maxted, Racine, Bennett, Pinnock, Traore, Sinclair, Noble, Kelly, Frear, Moore, Murphy.
Subs: Clough, Carter, Tubbs, Jefford, Chemlal, Doidge, Elliott, Hickford, Marsh-Brown, Hall.
Blues First Half XI: Legzdins; Spector, Morrison, Grounds, Cogley; Tesche, Gleeson, Arthur, Shinnie, Maghoma; Donaldson.
Blues Second Half XI: Kuszczak; Caddis, Shotton, Robinson, Grounds (Tiendalli, 59); Davis, Gleeson (Maxwell, 59), Arthur (Brown, 59), Fabbrini, Solomon-Otabor; Donaldson (Storer, 59).
Unused subs: Lubala, Bernard, Weaver.