Two goals in the opening 19 minutes put Scunthorpe on the way to three points and only their second win in nine games in League One.
Leading marksman Gary Hooper fired the Iron in front after seven minutes at Glanford Park with his 26th goal of the season and winger Kevan Hurst made it 2-0 12 minutes later with his second goal in successive home games.
After squandering a string of chances, Scunthorpe had to wait until the 79th minute before striker Paul Hayes made it 3-0 with his 16th of the season.
"Of course we're pleased to be back in the top six and with six home games still to play we have got to feel positive about a play-off place," said manager Adkins.
"This was our game in hand over some of our rivals and it was important that we won it. We played some good attacking football and created a lot of chances."