Kilmarnock dented Celtic's title aspirations further at Rugby Park as Joos Valgaeren rescued a point for the champions.

The Belgian defender struck in the second half after Andy McLaren's first-half header to reduce the deficit on Scottish Premier League leaders Rangers to four points.

But Martin O'Neill's men - who in midweek ensured they remained in Europe beyond Christmas for the first time in 23 years - had ample opportunities to have taken all the points.

Buoyed by their endeavours in Vigo, Celtic started positively and came within inches of taking the lead after five minutes.

First Stilian Petrov signalled their intent with a low right-foot shot from 22 yards after Henrik Larsson had knocked Chris Sutton's ball into his path, but Gordon Marshall made a comfortable save.

But the former Celtic goalkeeper was well beaten two minutes later and needed the post to come to his rescue.

Larsson got on the end of John Hartson's cross and his header was deflected by Greg Shields and went behind off the woodwork.

But Celtic were guilty of squandering a great chance to take the lead in the 10th minute.

Sutton headed the ball into the path of Bobo Balde and his shot from two yards was turned away by a relieved Kilmarnock keeper, although the giant defender should have hit the back of the net.

Marshall was a busy man and needed to be alert in the 18th minute to keep his side on level terms.

Sutton flicked on Valgaeren's throw-in and Larsson swivelled and shot low, but the Kilmarnock man saved low to his right.

But Jim Jefferies' side - who had won their last two games - stunned the champions by snatching the breakthrough with their first real chance of the game after 19 minutes.

Shaun Dillon swung in a dangerous free-kick and McLaren's glancing header from nine yards flew past the despairing dive of Robert Douglas and nestled in the top corner of the net.

Celtic tried to strike back immediately, but great awareness by James Fowler prevented them from doing so.

Chris Innes was penalised for a foul on Hartson just outside the box and Larsson sent a right-foot curler over the wall and beyond Marshall, but the Killie man got back to head over the bar.

Ally Mitchell resorted to extreme measures to stop Celtic breaking away with a challenge from behind on Alan Thompson which earned the Kilmarnock midfielder a booking.

Celtic seemed to have a good call for a penalty in the 35th minute after Hartson appeared to be pulled back by Innes from Balde's long ball.

But Kilmarnock broke away with intent again minutes later and the visitors needed McNamara to come to the rescue.

McLaren spotted Gary McSwegan on the overlap and teed the ball into his path, but his right-foot shot was headed over the crossbar by the versatile Scotland international.

Kilmarnock again caused the visitors problems from a set-piece situation just two minutes after the restart.

Hartson headed Mitchell's corner to Fowler and he controlled and struck a sweet right-foot shot just past the upright from 22 yards.

But Celtic pushed Sutton further forward in search of an equaliser and it almost paid off in the 52nd minute when he played the ball across the face of goal, but Larsson was unable to get a touch.

Celtic were having problems getting their flowing passing game together and Kilmarnock were hanging on to their advantage.

Larsson eventually did get away down the left channel in the 62nd minute after being played through by Thompson, but his cross was cut out by the alert Marshall.

But moments later Kilmarnock somehow survived after Celtic hit the post twice in a matter of seconds.

Agathe directed Thompson's cross into the path of Larsson and he drilled a powerful right-foot shot against the woodwork and Sutton did the same with the rebound from three yards out.

But it was only a matter of time before Celtic drew level and they did that in the 66th minute.

Hartson directed Thompson's cross back into the danger area and Valgaeren headed past Marshall from close range.

The men from Glasgow were now expected to go and take the points and Larsson should have put them ahead in the 71st minute.

He peeled away off his marker to get on the end of Petrov's corner, but his header slipped just past the upright.

O'Neill brought on wide man Steve Guppy for Petrov before Hartson failed with an audacious chip after Larsson had flicked the ball into his path.

It did not look like the winner would come for the champions as Larsson again headed wide from Agathe's cross before Guppy's weak attempt was easily saved by the Kilmarnock keeper.

The home side could have even robbed Celtic of the points with time ticking away as Steve Fulton picked Canero out unmarked in the box, but he fired wide with just Douglas to beat.

Hartson headed over moments later before they were denied a clear penalty when he was cut down by Fowler.

O'Neill was understandably furious at the final whistle as he attempted to speak with the official - but he should have been venting his anger at his players for missing so many chances.

Teams

Kilmarnock: Marshall, Fowler, Innes, Shields, Dillon, Canero, Mahood, Fulton, Mitchell (Sanjuan 68), McSwegan (Boyd 74), McLaren (Dargo 89).

Subs Not Used: Meldrum, Hay.

Booked: Mitchell.

Goals: McLaren 19.

Celtic: Douglas, McNamara, Valgaeren, Balde, Agathe, Lambert, Petrov (Guppy 77), Sutton, Thompson, Larsson, Hartson.

Subs Not Used: Gould, Fernandez, Maloney, Crainey.

Booked: Thompson.

Goals: Valgaeren 66.

Att: 9,225

Ref: W Young (Scotland).