Hemmings' 16th goal of the campaign accounted for AFC Telford United on the final day at The Jakemans Stadium.
The Pilgrims moved into their highest position of the season in the process while Hemmings was crowned as United's player of the year at full-time.
It was a fairly low-key affair with both sides clear of relegation danger and United’s play-off hopes all-but extinguished following their midweek draw at Nuneaton Town.
Kabongo Tshimanga, making a third successive start, had two presentable chances and sent a 22-yarder wide before testing Ben Wilson from slightly closer in.
Telford’s clearest opportunity before the break saw Jordan Lussey’s free-kick blocked by the United wall and Amari Morgan-Smith’s follow-up deflecting wide.
Hemmings thought he had given United the lead at the end of the first half but his effort was ruled out for offside after Tshimanga had been penalised for his part in the build-up.
The Pilgrims were desperately unlucky not to take the lead moments after the break when Reece Thompson headed against the inside of the post following Brad Abbott’s cross from the right. Andi Thanoj saw his follow-up palmed to safety by keeper Wilson.
Boston took the lead in the 59th minute when Dominic Smith was penalised for handball and HEMMINGS duly stroked home the resultant spot-kick.
Visiting skipper Shane Sutton made a stupendous block to keep out a goalbound Tshimanga drive following a Stephen Brogan centre from the left.
Telford had late half-chances through John Marsden and Ellis Deeney but the Pilgrims comfortably held out to end the campaign on a winning note.
Boston (4-4-2): George Willis; Ben Middleton, Ryan Qualter, Jordan Keane, Stephen Brogan; James Clifton (Jonathan Wafula 71), Brad Abbott, Andi Thanoj, Ashley Hemmings; Reece Thompson (Jamie McGuire 90), Kabongo Tshimanga (Gregg Smith 85). Subs (not used): Jack Withers, Jon Stewart (gk).
AFC Telford (4-4-2): Ben Wilson; Ross White, Dominic Smith, Shane Sutton, Bob Harris; Jordan Lussey (John McAtee 73), Jonathan Royle (Jordan Murphy 86), Ellis Deeney, Elliot Newby (John Marsden 65); Amari Morgan-Smith, Marcus Dinanga. Subs (not used): Kane Richards, Jasbir Singh (gk).
Referee: Ricky Wootton.
Attendance: 1,075 (62 visitors).