Murray Davidson's scrappy first-half opener was enough to earn the McDiarmid Park outfit another three points in a sequence that was sparked by an unlikely triumph over champions Celtic in mid-September.
With just a minute remaining, the persistent Nigel Hasselbaink - who earlier missed an open net - finally scored the second the Perth men deserved before James Fowler netted a consolation for Kilmarnock.
Niall McGinn was on target as Aberdeen extended their unbeaten run to 11 games and left Dundee United winless in six after a 1-1 draw.
John Rankin's 22nd-minute goal was cancelled out eight minutes into the second half by Aberdeen striker McGinn, who netted in Northern Ireland's midweek draw in Portugal on the occasion of Cristiano Ronaldo's 100th cap.
A late goal from Colin McMenamin, his first of the season, was enough to earn Ross County a 3-2 win over Hibernian - their first home victory in the SPL.
McMenamin came off the bench and made a big impact grabbing what proved to be the winner with seven minutes to spare.
In an entertaining match Leigh Griffiths gave Hibs the lead in the sixth minute but Stuart Kettlewell levelled three minutes later. Iain Vigurs then gave County the lead in the 34th minute before Hibs equalised through James McPake on the stroke of half time.
The match looked to be heading for a draw in an equally entertaining second half but super-sub McMenamin popped up with the winner.
- Nigel Hasselbaink