Marcus Law made changes following the midweek defeat to Redditch United with Brett Solkhon coming into the team to partner Paul Malone at the heart of the defence with James Haran switching to right-back while Lewis Hornby returned to the starting line-up.
It proved to be a forgettable first half with few chances as Wilson Carvalho saw an effort saved while Rene Howe shot wide with Kettering’s best openings.
Dorchester had the better chances early in the second half with Ben Wood’s deflected effort hitting the bar and then they were presented with a big opportunity when they were awarded a penalty but Jake Smeeton smacked his spot-kick against the woodwork.
The Poppies piled the pressure on after that and they finally made the breakthrough when Howe was on hand to tap home following a goalmouth scramble.
Paul Malone made a crucial header to deny Dorchester a leveller but Kettering saw things out to secure the success.
AFC Rushden & Diamonds extended their unbeaten run in the Evo-Stik Northern Premier League Division One South to 13 matches but they were held to a 1-1 draw by Market Drayton Town at the Dog & Duck.
Diamonds were boosted by the return of influential central defender Liam Dolman after a calf injury.
After a quiet start, Diamonds went close when Richard Bunting sent a 30-yard effort just wide before Shariff was off target with a header.
But Diamonds did take the lead on the stroke of half-time.
Taylor Orosz was shoved over in the penalty area and Shariff stepped up to slot home from the spot.
Market Drayton started the second half well and James O’Neill’s free-kick was well saved by Matt Finlay.
But the visiting frontman went one better on 61 minutes when another set-piece beat Finlay to level things up.
Jake Newman had an effort parried away for Diamonds but both sides had half-chances which weren’t converted as the game ended in stalemate.
Corby Town’s problems intensified at the wrong end of the Evo-Stik Northern Premier League Premier Division as Barwell claimed a comfortable 2-0 success at Steel Park.
Gary Mills handed starts to Jordan Smith and Izale McLeod who both joined the club this week while ex-Steelman Callum Ball was included in Barwell’s line-up but Cleveland Taylor missed out on a reunion with his former club due to a one-match ban.
Liam Marshall also returned at left-back for the Steelmen and it was the hosts who had the first chance when McLeod’s lovely inside pass found Stefan Moore but Liam Castle made a fine save to deny him.
However, Barwell soon took control and Louis Connor tipped Joseph Ballinger’s shot over before they took the lead.
Connor raced from his goal and pulled down a visiting player just outside the left of the area. And Ball stepped up to whip a left-footed free-kick into the corner.
Connor beat away another effort from Ball as the visitors chased a second and, after Smith had headed straight at Castle, the Corby stopper was back in action as he made another decent stop from Nigel Julien after he cut in from the right.
Ball took aim with a fierce long-range effort just before the break and Connor again dived full-length to turn it round the corner.
But Barwell did double their lead five minutes into the second half when Brady Hickey headed home after a corner had been flicked on.
Ball fired over soon after while Moore fizzed a long-range effort wide at the other end.
McLeod had a chance to reduce the arrears when he went through but scuffed his shot wide and that was as close as Corby came as Barwell comfortably saw things out.