Magilton, who earlier received a vote of confidence from club owner Marcus Evans, has been increasingly under fire from Blues fans, but they are now just four points off the play-offs.
Nottingham Forest fought hard throughout and were desperately unlucky not to claim a share of the spoils and they remain in real relegation danger.
Forest started the better with Nathan Tyson testing Richard Wright, but Town went ahead on 14 minutes when Tommy Miller's curling free-kick was headed past his own keeper by visiting skipper James Perch.
Luciano Civelli and Gareth McAuley shot wide before Joe Garner had the ball in the net for Forest from Chris Cohen's free-kick, but it was ruled out for a foul on Richard Wright.
Forest also started the second half on top with Richard Wright making good saves to parry a Matt Thornhill shot and claiming a Lewis McGugan free-kick.
Paul Smith made a terrific save to beat away Alan Quinn's 25-yarder before sub Jon Walters blazed over after a clever one-two with Pablo Counago.
Town doubled their advantage on the hour when McAuley's slide-rule ball released David Wright and he drove the ball past Smith at his near post.
Counago had a close-range shot blocked by Brendan Moloney, before Smith palmed away a firm McAuley header and Counago couldn't quite convert the loose ball, as Town tried to sew up the points.
The fact they didn't gave Forest hope and after Richard Wright made two excellent saves to deny McGugan piledrivers, the visitors halved the deficit when Tyson swept home sub Garath McCleary's cross.
Walters shot over and Smith saved from Jon Stead but Forest were inches away from an equaliser on 87 minutes, when McGugan's low drive hit the post and only a superb McAuley challenge stopped Tyson sweeping home the loose ball.