Derek McInnes insists his side needs to take more responsibility after a second-half winner sent Arbroath four points clear at the top of the cinch Championship.
The Kilmarnock gaffer suffered his first defeat in the league since taking charge at Rugby Park early last month when Jack Hamilton's shot squirmed through the gloves of keeper Zach Hemming.
Part-timers Arbroath were reduced to 10 men in the dying minutes when substitute James Craigen saw red for a lunge.
But the Ayrshire side couldn't take advantage at Gayfield as this Friday night fright saw them drop more points in the race for the title.
"We spoke about the fact it might be a mistake that wins it and unfortunately for us it was ours," McInnes said. "We huffed and puffed before the end but Arbroath did what Arbroath do which is stay in the game and get their points.
"We needed to take more responsibility to get on the ball. Sometimes when conditions are as bad as they are, players abdicate a wee bit of responsibility to make the game go our way.
"There was plenty of effort from the players – but it's going to take more than effort to win the league. It's going to take concentration and responsibility to come away from a place like this with something.
"There's not too many positives. If we're going to get back into the Premiership then we're going to need to show a bit more of ourselves."
Kilmarnock chief McInnes made three changes to the side which secured a narrow 1-0 win at home to Inverness Caledonian Thistle last Saturday.
Jason Naismith and Chris Stokes replaced Lee Hodson and Jack Sanders in defence while on-loan Aberdeen midfielder Dean Campbell made his debut with Oli Shaw dropping to the bench.
Another new recruit, Dundee United loanee Declan Glass, was among the nine substitutes which can be listed by clubs on a matchday with five allowed to be used.
Perhaps unsurprisingly, it was a blustery night on the fringe of the North Sea and it was Arbroath who served notice of their intent by carving out the first chance in the 11th minute.
Hamilton chested the ball down from the edge of the box into the path of Scott Stewart whose low effort had Killie No 1 Hemming scrambling across his territory.
Truth be told, it was a first half which wasn't pleasant on the eye although Killie took aim a couple of minutes before the break in search of the opener.
A move with purpose resulted in Daniel MacKay unloading from distance with Smokies stopper Derek Gaston gathering the ball at the second attempt.
However, disaster struck for Killie in the 55th minute as the home side took the lead.
Dylan Tait, himself on loan from Hibernian, was barged off the ball far too easily by Hamilton who raced forward and fired in a shot which Hemming fumbled into the bottom corner of the net.
Killie needed to produce a response but had penalty claims turned down four minutes later when a Rory McKenzie volley was handled by Thomas O'Brien.
Time was running out for Killie and it was both excellent goalkeeping and profligacy that denied them an equaliser in the 74th minute.
Fraser Murray did well to deliver a near-post cross for McKenzie whose effort was instinctively saved by Gaston with Kyle Lafferty sending the rebound wide.
Arbroath faced a nervy finish when Craigen was sent-off in the 85th minute for lunging in on McKenzie but they held on for a famous win as Killie head back to the drawing board.
Smokies manager Dick Campbell said: "It was never going to be a classic game due to the conditions and time of year but I thought we shaded it.
"I'm very, very happy but we've seen in spells that Kilmarnock are going to get better so let's not count our chickens."
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