French star Didier Agathe scored a priceless first goal for Celtic in the dying seconds to give the Bhoys a 2-1 victory over Dundee.

After Neil Lennon's £5.75million arrival this week all eyes were on the midfielder, but it looked like he would have to settle for a point at Dens Park as Tom Boyd's own goal cancelled out Stilian Petrov's opener.

A draw would have been a fair result, but with time running out Agathe headed home at the far post to extend Celtic's lead at the top of the Premier League to seven points.

In the context of the season this could prove the decisive moment if the Parkhead side go on to lift the title and the signing of Lennon could also prove vital.

Lennon, whose touches were greeted with cheers from the green and white faithful, made his presence felt from the first whistle and made a vital challenge on the edge of the box to thwart Claudio Caniggia as he shaped up to shoot.

But the former Crewe man was soon celebrating a goal in only the fourth minute when Bobby Petta fed the ball to Lubo Moravcik, who played the ball back into the path of Stilian Petrov, who slotted it home past Marco Roccati.

Dundee had to reorganise in the sixth minute when Marcello Marrocco hobbled off to be replaced by Chris Coyne, but that did not seem to affect them as they came back strongly.

Ivano Bonetti's side went agonisingly close in the 15th minute when Giorgi Nemsadze crossed to Beto Carranza, but he fired just past the upright with Douglas well beaten.

Dundee, however, should have taken the lead moments later when Joos Valgaeren failed to cut out a cross from Carranza. The ball fell to Juan Sara inside the box, but Petrov made a vital challenge to deny him a glorious goal-scoring chance.

The home side refused to lie down and in the 27th minute Steven Tweed should have done better when Nemsadze picked him out from a corner kick, but he headed harmlessly across the goalmouth.

But a minute later Lennon almost created Celtic's second when he played Moravcik clean through on goal, but the Slovakian's first touch let him down and Roccati was able to make a telling block.

Celtic were struggling to come to terms with the pace of Caniggia and on the half hour they had Valgaeren to thank for keeping their lead intact.

The Argentinian striker ran onto Carranza's pass and took it round Douglas, but the Belgian defender got back to clear off the line.

Douglas then had to be alert in the 35th minute when Marcello Marrocco's cross took a deflection goalward off Johan Mjallby, but the goalkeeper made a vital save on his line.

But Dundee continued to threaten and they carved out a great chance in the 38th minute when Caniggia found Smith wide on the right and he swung the ball into Sara, who jumped above Mjallby but headed just over the bar.

Moments later and Rae saw the chance of glory when the Celtic defence seemed to open up in front of him, but the midfielder hit a fierce right-foot effort over.

In the final seconds of the half Celtic should have done better when Moravcik fed the ball through to Thompson, who was presented with a great chance after Smith had slipped, but he fired straight at Roccati.

Celtic could have extended their lead just three minutes into the second half when Petta's corner found Valgaeren at the near post, but the defender volleyed just past the upright.

But Dundee deservedly drew level in the 55th minute and it came fortuitously after Caniggia had put the Celtic defence on the back foot again.

The striker crossed towards Sara in the box, but Celtic skipper Tom Boyd, under pressure, intercepted and headed past his own keeper Douglas and into the corner of the net.

Celtic's uncertainty at the back was again evident on the hour mark when Sara played the ball through to Caniggia, who rounded Douglas before firing into the side netting from a tight angle.

Dundee carved open the Celtic defence on a number of occasions, but the visitors finished the stronger.

The home side thought they had taken the lead in the 73rd minute when Carranza picked out Caniggia with his free-kick, but Douglas pulled off a great save to his right to keep out the striker's header.

They almost regained the lead in the 79th minute when Henrik Larsson played Johnson into space on the left and he fired across the face of goal, Coyne deflecting the ball just past the upright.

Johnson squandered another great chance to put Celtic back in front with five minutes remaining when Larsson played the ball through to him in the box, but he guided his effort just over the bar.

But nobody could forecast the drama at the end of the game as Celtic grabbed the points.

Petrov's corner caused a huge goalmouth scramble and the ball appeared to strike Mjallby's arm before coming off Tweed and on to Agathe at the far post to head home.