Kieron Morris struck early in the second half as Tranmere moved four points clear of fourth-place Sutton United with 51 points and they cut Forest Green Rovers' lead to eight points at the top.
Story of the match
Tranmere were on the front foot early on as Lee O'Connor had an early effort cleared off the line after Peter Clarke headed the ball across goal.
Moments later, Paul Glatzel was unlucky not to put the hosts on the board with a flicked header which was well saved by Stevenage goalkeeper Christy Pym, who denied him again two minutes later.
In the 16th minute, Luke Norris received the ball in Tranmere’s half before laying it off to Jake Taylor on the left and he drove into to the box and played it across goal, forcing Ross Doohan to get down and save.
In the closing stages of the first half, Norris’ low driven cross almost ended up in the back of the net, but Taylor couldn’t quite connect with the ball.
Within two minutes of the restart, the hosts were in front. A cross from the right found Hemmings who laid the ball off to Morris who beat Pym in the bottom right corner.
Ten minutes later, the visitors came close to grabbing an equaliser. O’Neill’s cross fell to the head of Norris who nodded it back to Jake Reeves. He had a go, but was denied on the line by the head of Nathaniel Knight-Percival.
Luke O'Neill created a promising opening for himself before snatching at his effort and five minutes later, Charlie Carter shot straight at Doohan.
Norris went close as his acrobatic effort whistled just wide of the post and in the 87th minute, Hemmings saw a header also fly back off the post after neat play from Josh Hawkes and Calum MacDonald on the left-hand side.
Man of the match: Calum MacDonald
He was excellent on the left side of defence and combined well with Hawkes to nearly set up Tranmere's second. Overall, a solid performance.