An adventurous attacking display from Dundee United saw them get back to winnings ways at Tannadice.
They took the lead early on through Nadir Ciftci before Killie equalised against the run of play on 38 minutes thanks to a well-placed shot from Manuel Pascali.
The home team waited just three minutes before edging back in front, with man-of-the-match Stuart Armstrong shooting past keeper Craig Samson.
They continued to dominate the opposition and should really have converted more chances than they did.
However, the scoreline gave a more accurate reflection of the play when United substitute Aidan Connolly tapped the ball home in the second minute of stoppage time.
The Tangerines had made four changes to the line-up that started the defeat to Motherwell before the international break.
Into the side came Sean Dillon, Callum Morris, Charlie Telfer, Gary Mackay-Steven and Ciftci, taking the place of John Souttar, Blair Spittal, John Rankin, Connolly and Ryan Dow. Rankin was injured and the others sat on the bench.
Killie, bizarrely wearing a black and tangerine change strip, kicked off and the match was only six minutes’ old when the home team took the lead with a fine goal.
The impressive Chris Erskine did well to regain possession after his poor freekick was cleared.
He won the ball back at the half-way line in front of the George Fox Stand and played it forward to Armstrong.
The midfielder’s clever pass then sent Ciftci clear and the Turk finished in style with a right-foot shot from just inside the box that flew across Killie keeper Samson and into the far corner of the net.
Ciftci broke clear up the left on 20 minutes after a mis-control by Mark Connolly, cut inside and looked set to shoot but fell inside the box and the chance was gone.
On 25 minutes, the Tangerines carved Killie open again.
Armstrong started the move by picking out Mackay-Steven just inside the opposition half.
Mackay-Steven went on a mazy run before flicking the ball into the path of Telfer, whose shot was blocked.
Just three minutes later, Samson tipped over a 30-yard freekick from Mackay-Steven after Ciftci had been fouled by Sammy Clingan.
Erskine then appeared to send Mackay-Steven clear as the hosts continued to boss the match but the flag went up for offside as soon as he touched the ball.
On 35 minutes, Erskine had a few choice words for Ciftci after the Turk chose to shoot rather than square the ball to his teammate for what would have been a certain goal.
Against the run of play, the visitors levelled on 38 minutes.
It was a bad goal to concede from United’s perspective.
An Alexei Eremenko pass was allowed to travel further than it should have done and reached McKenzie.
He smashed a shot off the post and it rebounded to the edge of the box to Pascali, who sidefooted the ball into the net when, once again, a United boot should have cleared it.
While the bad stuff was happening at the back, more good play at the other end of the park put Jackie McNamara’s men in front again three minutes before the break.
Armstrong was the scorer and he created it for himself with a clever run across the front of the box. He then exchanged passes with Erskine before firing home from 15 yards.
The second period was only two minutes old when Ciftci nearly grabbed his second goal of the game, blasting an Armstrong cutback against the body of Samson from close range at the near post.
Telfer’s long-range strike on 52 minutes whizzed just wide as Killie were pinned back once again before Armstrong broke forward only to shoot straight at Samson.
United continued to have the better of the play but there was a scare for them with just a couple of minutes of regulation time left when Ross Barbour’s shot was defelcted just wide.
However, it was the Tangerines who hit the target in stoppage-time thanks to yet another sweeping move started by Armstrong.
From in front of the dugouts the midfielder pinged a cross-field pass all the way to sub Blair Spittal out on the left wing and the youngster did well to find Connolly with the cutback and the ball was duly fired into the net to make it 3-1.
Attendance: 6,664.
Dundee United: Cierzniak, Dillon, Morris, Fojut, Townsend, Paton, Armstrong, Telfer, Mackay-Steven (Spittal 70), Erskine (Dow 70), Ciftci (Connolly 84). Subs not used: Szromnik, Watson, Butcher, Souttar.
Kilmarnock: Samson, Barbour, Hamill, Connolly, McKenzie, Clingan, Eremenko (Johnston 67), Chantler, Magennis (Miller 67), Pascal, Muirhead (Cairney 73). Subs not used: Brennan, Ashcroft, Slater, O’Hara.
Referee: John Beaton.