Former Dundee United pair Michael Gardyne and Brian Graham did their bit to help their former side as they played major parts in County’s victory at Rugby Park.
Gardyne crossed for Alex Schalk to head in the eighth-minute opener and substitute Graham added a second in the last minute with a well-judged lob over Jamie McDonald.
The victory took the Staggies back into fourth place in the table but leaves Killie even more vulnerable to a Dundee United fightback.
The Ayrshire side remain eight points ahead of the Tangerines but have now played two games more.
Manager Lee Clark was unhappy with his side’s lacklustre performance.
He said: “It’s put us in a tough position but there still needs to be fight.
“At half-time I didn’t feel we had enough showing the right fight for the position we are in.
“I thought we started quite well on front foot but we gave two horrific goals away from a defensive point of view.
“I told the players in no uncertain terms at half-time but if you’re conceding and not scoring it’s difficult.”
By the reaction of the home supporters when the final whistle sounded, they do not have a lot of hope in their side steering clear of trouble.
Kilmarnock made the early running but it was County who went ahead with their first real attack, Schalk glancing in Gardyne’s pin-point cross.
The home defence looked nervy throughout and Clark’s side rarely threatened, though midfielder Gary Dicker did have the ball in the net only for referee Stephen Finnie to blow for a foul on Staggies keeper Gary Woods.
Killie pushed for an equaliser but County’s Liam Boyce hit their post and Graham, who replaced another former United man David Goodwillie, sealed the points as time ticked away.
Attendance: 2,633
Kilmarnock: MacDonald, Hodson, Balatoni, Findlay, Faubert (O’Hara 73), McKenzie (Carrick 70), Kiltie, Dicker, Obadeyi (Higginbotham 31), Magennis, McHattie. Subs not used: Brennan, Ashcroft, Slater, Frizzell.
Ross County: Gary Woods, Foster, Quinn, Davies, Fraser, Irvine, Franks (De Vita 83), Martin Woods, Gardyne, Schalk (Boyce 60), Goodwillie (Graham 72). Subs not used: Robertson, McShane, McLaughlin, Foden.
Referee: Stephen Finnie.