Kilmarnock outlined their desire to be treated seriously as title contenders by overcoming champions Celtic at Rugby Park to remain Rangers' closest Scottish Premier League challengers.

Second-half goals from Mark Roberts and Ally Mitchell did the trick for Bobby Williamson's men who have lost only once in this league this term.

Celtic even found themselves reduced to 10 men in the closing minute when Stephane Mahe was ordered off for a second bookable offence in what was an ill-tempered contest. Yet it was an assured display from the Ayrshire outfit who punished a makeshift Celtic backline twice after an even, if scrappy, opening 45 minutes.

Jozef Venglos now takes his team to Zurich for the return leg of Celtic's UEFA Cup second round meeting with the Swiss knowing more will be required throughout his side.

In attack, the visitors were again badly short of firepower with Henrik Larsson's off-day only serving to highlight how reliant Celtic are on his talents with Harald Brattbakk again below-par.

In addition to Mahe seeing red, there were seven further bookings, but amid the frenzied approach, Kilmarnock's football was the more incisive.

Celtic were forced into a change after 23 minutes when Burley limped off with an apparent muscle strain to be replaced by Phil O'Donnell with Vidar Riseth moving into the centre. Larsson missed a real opening after 35 minutes after being put through by Donnelly, the Swede curling his shot with the outside of his foot beyond the reach of Marshall but wide of the mark.

Celtic threatened again two minutes later, this time Larsson finding Brattbakk but Kevin McGowne's saving tackle denied the out-of-touch forward a shooting chance.

After 55 minutes, Kilmarnock moved ahead when Ally Mitchell's cross from the right picked out Roberts whose glancing header defeated Gould from close range. Brattbakk had a chance to level at once for the visitors but after cutting inside well delayed his shot long enough for his effort to be deflected wide.