Gary Wales heaped more pressure on under-fire Dundee United manager Gordon Chisholm with a last-minute winner for Kilmarnock in the Bank of Scotland SPL at Rugby Park.

Gary McDonald gave the home side a deserved lead at the interval when his intended cross in the 37th minute swerved into the United net.

In-form Collin Samuel looked to have salvaged a point for Chisholm when he pounced for the equaliser on 51 after David McCracken's header was pushed out by Alan Combe.

But substitute Wales showed terrific striker's instinct and admirable technique to fire home inside a crowded penalty box with just seconds remaining in normal time.

The victory consolidates Jim Jefferies' side's position in the top six but represents more bad news for Chisholm, whose team has won just twice away from home this season and face a daunting set of fixtures in the new year.

The first opportunity of the game fell to Colin Nish, handed the first chance to fill the boots of Rangers-bound Kris Boyd,- who it was revealed at half-time has donated £20,000 to Killie's youth system.

The former Dunfermline striker collected a hopeful Garry Hay clip into the box but pulled his shot wide of Derek Stillie's left-hand post in the fourth minute.

Five minutes later Killie had an even better chance to take the lead when Steven Naismith drifted beyond a static United defence before a heavy touch allowed Stillie to smother his effort wide.

Naismith wasted another gilt-edged opening on 18, firing wildly over from 10 yards out after intelligent build-up play from Murray - recalled due to the injury to Allan Johnston - and McDonald.

The first threat from the visitors - who recalled Stuart Duff and Lee Miller in place of the injured Peter Canero and Grant Brebner - arrived in the 33rd minute, a swift counter-attack culminating in Barry Robson narrowly failing to apply a decisive touch to Mark Wilson's astute pass.

Four minutes later the home side got the breakthrough their domination deserved when McDonald attempted to cross to the back post but cut across the ball which resulted in it swerving into the top left-hand corner of the hapless Stillie's net.

Having been witless for the duration of the first half, the Tangerines somehow mustered an equaliser just six minutes after the interval.

From Barry Robson's left-wing corner, a firm header from McCracken was pushed out by Combe but Samuel was there to fire home his third goal in four games.

The goal was not however the cue for some entertaining football, a scrambled effort from Jim McIntyre in the 67th minute being the only subsequent notable action at either end in the first half of the second period.

Realising the need for some additional impetus Jefferies withdrew Murray and threw on another striker in Wales, a move which resulted in Naismith dropping back into a midfield role for the final quarter.

It did not have the desired effect though as both sides continued to labour for the winner, a weak Miller free-kick being the best United could offer at this juncture.

It seemed to energise his team-mates though and the former Hearts striker and Alan Archibald threatened with a couple of half-chances either side of the 85-minute mark.

Jefferies threw on Paul di Giacomo for Nish with a couple of minutes remaining as the home side showed some late urgency.

The ploy paid off as, with just over 30 seconds of normal time remaining, Wales pounced on a loose ball in the box to fire low past Stillie into the bottom right-hand corner and seal the points for the Ayrshire side.