Harriers made their final substitutions on 71 minutes when Corbett and Davies replaced Clarkson and Faulds.
Then Swifts made changes a minute later as Cooper and Hart came on for Marsh and Langford.
Broughton was denied by his own player on 74 minutes after the ball fell for him in the penalty area.
His shot struck Lewis near the line after the young substitute had tried to meet a Foster left-wing cross which was palmed out by Hipkins.
The Swifts keeper was called into action again a minute later to make a fine double save from Broughton's header and Sall's close-range follow-up.
Swifts made a third substitution on 77 minutes when centre-back Anthony came on for former Harriers man Mulders.
Broughton hooked a difficult volley over the bar on 80 minutes after running on to Corbett's high through-ball from midfield.
Foster made it 5-1 three minutes from time, tapping home from close range after Broughton had flicked on Stamps's right-wing corner.
Foister was denied a hat-trick on the verge of full-time when he glided into the box but was foiled by a good save from Hipkins.
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