Kilmarnock slipped to the foot of the Scottish Premiership after Ashley Hay's towering header and slapstick second earned Dundee their fifth win of the season.

An open encounter was settled by Hay in the final 10 minutes - after the forward himself had an effort disallowed - to ensure Steven Pressley's side clambered above their city rivals and into fourth place.

Joe Bevan - a terrific threat on the right of attack - shattered the deadlock when he latched on to a searing Ethan Hamilton run and through ball, chopped onto his left foot and swept beyond Nico Mantl.

The German goalkeeper making his Kilmarnock debut had already denied Bradley Fink, whose close-range header should have found the net, before the striker bundled the rebound off a post.

Mantl would have a painful part to play at the death.

Long before the chaotic finale, on the stroke of half-time, he was rendered helpless by the shoddy marking in front of him when Hamilton steamed unguarded into the box from a corner but side-footed over from six yards on the volley.

Kilmarnock saw first-half glimpses through Greg Kiltie and Joe Hugill, and the latter drew a phenomenal stop from Owen Goodman early in the second period.

Kiltie lofted the ball over the top for the striker, who set himself, and unleashed from 12 yards. But Goodman leapt to his right and tipped over the top.

Hugill would have his moment, however, converting from the spot after George Stanger hit the deck from a Kilmarnock corner.

But Dundee regrouped and went again, Hay diverting home with his left arm after Cathal McCarthy had completely misread the flight of a cross. The defender's blushes were spared by the VAR officials.

Hay was unperturbed, soaring into the Dundee night to power home a header with seven minutes to play.

As if to underscore the problems besieging Neil McCann at the back, his new keeper went walkabout in the dying embers allowing Hay to saunter into the box and slot into an empty net. When it rains, it pours.

Pressley's reputation, and Dundee's resilience, were burnished again here.

In the early stages, the manager seemed to favour a more direct approach, peppering the wide channels with balls over the top and down the sides, and allowing the exceptional Bevan to wreak havoc with his speed and trickery.

Bevan was the game's stand-out performer before being forced off on 60 minutes. The hope, for Dundee fans, is that the change was chiefly a precaution.

The quality of deliveries from those wide areas was impressive too.

Charlie Reilly bent one in from the right for Hay's disallowed goal. Alan Forrest curled a superb ball in from the opposite flank where Hay took to the air with spring-loaded jump beyond anything Kilmarnock could muster.

Saturday's blip in Paisley is Dundee's only defeat in five league matches as they cling to the coattails of Hearts.

McCann tends to cut a spirited figure on the touchline, and you felt for the Kilmarnock boss as he watched a catalogue of errors unfold in his defence yet again.

His team are always brave in possession at the back, and built nicely in the opening throes, but by the endgame they were sickened by a series of mistakes.

McCarthy was lucky. He should have dealt with the cross for Hay's overturned handled 'goal'.

Nobody offered much of a challenge to the airborne Hay for his first legitimate effort, though, and Mantl, until then a pretty assured presence on his first Kilmarnock outing, sprinted out chasing a lost cause to snuff out any lingering hope of a draw.

Kilmarnock have now conceded a league-worst 26 goals in 11 matches while scoring a joint-lowest 11 at the other end.

The omens are not positive.

Dundee manager Steven Pressley: "The thing that really pleased me was after Kilmarnock scored and the momentum changed, we showed great resilience and determination and ran really hard.

"After the equaliser it is easy to feel sorry for yourselves. We didn't and we got a really important three points.

"We were reliant on a number of players. Joe Wright came in, Joe Bevan we had to change because he was cramping up. Matia Akinmbomi on loan from Bournemouth got his first taste of Scottish football. The squad has responded and is doing really, really well.

"We never set targets. The only target we set is to try to win the next game."

Kilmarnock manager Neil McCann: "When I went in at half-time I was disappointed at being behind but no panic, we knew the game would turn in our favour and I felt we did a lot of good stuff without that wee bit of polish.

"We got level, I felt we could go on and win, and the ball comes into the box and Ashley Hay gets a header and that's really disappointing.

"I felt Tyreece John-Jules is fouled [in the lead-up to the goal] and Duncan Nicolson gives a corner.

"The third goal is just a poor decision from the goalkeeper.

"If anybody in that dressing room thinks you just roll over – no, you don't. You get back to work. We want to put on a show against St Johnstone on Saturday. We know exactly what we are up against and what we have to do better."