Defender Nathan Stanton brought Marc McKeever down in the box and Wayne Carlisle stepped up to thrash the spot-kick home off the body of goalkeeper Tommy Evans.
Stanton's annoyance led to him being shown a red card following the goal, after showing dissent.
"We were green and naive at times. After going two goals up we needed to step up a gear, but we almost invited them to come and have a go at us," said Laws after seeing his side surrender a comfortable lead.
Scunthorpe almost got off to a quick start when a smart back-heel from Wayne Graves was collected by Martin Carruthers and his first-time effort was palmed out by Scott Howie.
Rovers were finding the pace of the home side difficult to come to terms with, but they almost snatched an 11th minute lead when a Paul Tait shot ricocheted of James Cotterill.
However Scunthorpe came back and after a Graves shot was blocked the ball fell to Caruthers who promptly netted, but he was ruled offside.
The Iron's persistence eventually paid off. Peter Beagrie played the ball into the path of Steve Torpey who laid it off to Andy Dawson and he steered the ball home after 16 minutes.
A smart interception by Matt Sparrow prevented Robert Quinn getting in on the target and then the home side picked up the pace again, adding a second goal after 25 minutes, as Stanton's shot was deflected home by Carruthers.
Substitute Scott Brough, replaced Beagrie who had a hamstring strain and he saw a curling shot go wide and then a fine tackle from Trevor Challis stopped Caruthers.
Rovers showed a positive approach after the break and reduced the arrears after 48 minutes when a looping cross from Carlisle saw Quinn get in to beat Evans with a header.
Scunthorpe replied with Torpey and Graves going close and superb individual skill by Brough ended with Torpey skimmimg the bar with a header.
Rovers came back again and Evans produces a brilliant save to deny Quinn's header.
"We made it difficult, we gave them a two-goal start but in the end it was a fantastic result thanks to our never say die efforts," said Rovers boss Ray Graydon afterwards.
"Wayne Carlisle showed great courage in taking the penalty."