Laws, who played more than 200 times for Forest, saw his Scunthorpe side snatch a win, as Gary Megson's shot-shy side failed to make the most of long spells of pressure.
There was a new look Forest formation and line-up, but there remained a familiar tale as they began with enthusiastic endeavour, but failed to turn their domination into chances.
Megson's side were completely on top during the opening period but, for all their neat build up, they lacked the cutting edge where it counts and now lie sixth from bottom in League One.
The first 20 minutes saw the home side almost exclusively camped in the Scunthorpe half but, despite the best efforts of a lively looking David Johnson on his first start since January, they could only muster two efforts on goal.
Kris Commons, pushed up into an attacking role alongside Johnson, was first to test keeper Paul Musselwhite with a powerful cross-cum-shot that Johnson almost managed to convert at the near post.
Johnson then did well to escape his marker and turn inside Andy Butler, but his shot lacked the power to trouble Musselwhite.
At the other end, Rune Pedersen was not troubled once, with Scunthorpe's solitary effort coming when Ian Baraclough rolled a short free-kick to Sharp, who hit a shot into the Forest wall.
After the break, both sides were more inspired, with Scunthorpe growing in confidence and Forest finally finding some cutting edge.
Forest's Gino Padula almost marked his full debut with a goal, as he drove a 15-yard shot viciously towards the top corner, forcing a fine save from Musselwhite.
While Pedersen was finally called into action at the other end, twice in the space of a minute as Sharp forced a full-length save from the Dane, with a crisp low shot and then turned provider, crossing for Steve Torpey who saw the keeper save bravely at his feet.
But he could do nothing when Sharp, newly signed from Sheffield United for £50,000, was allowed the room to turn deftly in the penalty area and fired a left foot shot into the back of the net from 10 yards.
In the end it could have been worse, as former Notts County midfielder Baraclough came close to adding a second, with a dipping shot that Pedersen did well to palm over.