The substitute showed great technique to finish acrobatically at the far post following George Carline’s long throw on the hour-mark.
Unfortunately Haydn Hollis limped off with a serious achilles injury after half an hour.
The victory moves Town up one to sixth and they are well in the play-off mix now.
Here are Liam Norcliffe’s player ratings from the game at the Silverlake Stadium...
1. Grant Smith 7
His eighth clean sheet in 11 games. A tad fortunate when a header from a corner trickled through his legs in the first-half. Made a couple of comfortable saves after the break and made an important punch late on as Eastleigh searched for an equaliser. Photo: Dean Atkins
2. George Carline 8
Another game where he showed his versatility, shifting to the left of a back three when Hollis went off injured before moving back to right-back after half-time. Brought a save from McDonnell early in the second-half from the edge of the box and then went close again when he headed wide from a corner. Solid. Photo: jason chadwick
3. Josef Yarney 8
Deserves a lot of credit for his performance on his first start since January. Was particularly good in the air in the second-half. Photo: Steve Flynn/AHPIX LTD
4. Haydn Hollis N/A
The one disappointment to come from today. He went off with an achilles injury after 30 minutes and Rowe said it is 'serious'. Photo: Dean Atkins