Celtic's Stilian Petrov was the toast of Parkhead after producing a superb second-half winner against Dundee to give manager Martin O'Neill his 12th win a row.

This was far from vintage Celtic but again they showed great resolution to snatch a victory when a draw looked the most likely outcome with Chris Sutton and Henrik Larsson having an off day.

The home side sweated and probed the Dundee defence all afternoon in search of a goal, but it was the little Bulgarian who supplied a match-winning header from Lubo Moravcik's cross to maintain Celtic's lead at the top of the Premier League.

Ivano Bonetti's Dundee side came to Parkhead with their tails up after the midweek victory over Dundee United and looked like frustrating Celtic and taking back a point with them before Petrov rewarded the home side's efforts.

This game promised goals and excitement with the visitors never out of the news, but it was Celtic who started brightest.

And the home side had calls for a penalty as early as the second minute when Swedish striker Henrik Larsson crashed to the ground under the challenge of Lee Wilkie and Barry Smith, but the referee waved away protests.

But it was the visitors who came agonisingly close to drawing first blood in the sixth minute when Juan Sara rose unmarked in the box to head Bonetti's corner against the crossbar.

Larsson then linked up with Moravcik outside the box in the 10th minute and the Slovakian tried his luck from the edge of the area, but goalkeeper Robert Douglas got down well to his right to deny Celtic the opener.

Dundee looked dangerous on the counter-attack, but it was the home side who were pressing for the first goal of the afternoon.

Jackie McNamara tried to thread the ball through to Larsson who was lurking menacingly in the box, but Shaun McSkimming was on hand to clear the danger.

Moments later and the home crowd were outraged when Larsson appeared to time his run perfectly in talking Moravcik's through-ball in his stride but the linesman had no hesitation in flagging for off-side.

But Celtic were denied taking the lead in the 18th minute by the heroics of Douglas when he somehow pushed over a header from striker Chris Sutton after a great ball from Alan Thompson.

Douglas again had to be alert in the 24th minute when Moravcik whipped in a dangerous cross from the left wing, but he comfortably claimed with Larsson and Sutton putting him under pressure.

Celtic continued to press and a minute later Thompson was inches away from giving his side the lead when he took the ball in his stride before unleashing a fierce low shot which flew just past the upright.

Petrov then went down in the box, somewhat theatrically, under the challenge of Alessandro Romano which sparked a furious reaction from the Italian.

But Larsson got his first sight of goal in the 29th minute when he found himself space in the box but lifted his effort just over the crossbar.

Romano became the first man in the referee's notebook in the 36th minute when brought Moravcik down with a reckless tackle.

From the resulting free-kick Celtic almost took the lead when Thompson swung in a dangerous cross from the left wing which Sutton got a touch to but it lacked the power to beat Douglas in the Dundee goal.

Thompson again threatened the visiting goal in the 38th minute when Petrov played him into acres of space on the left and the midfielder struck a powerful left-footed effort which flashed just past Douglas' post.

Douglas was again called into action in the 42nd minute when Moravcik left Smith on the floor on the left of the area and he tried to square the ball to Sutton across the face of goal but the Dundee keeper dived low to save.

Two minutes before the break and Larsson tried to find Moravcik in the box with a cross to the far post, but he could not keep his header down.

In the last minute of the half the Slovakian tried a dipping shot from outside the box which was just too high.

The home side upped the tempo after the break, but they were again hitting a brick wall as the Dundee defence remained defiant.

Celtic were concerned in the 49th minute when the reliable Johan Mjallby was caught late by McSkimming as he lost control of the ball and he escaped without even a booking.

Moravcik was presented with a shooting chance in the 50th minute, but McSkimming made a goal-saving block in the area to keep his side on level terms.

The Celtic fans began to grow with frustration, but Sutton could have settled the nerves in the 52nd minute when he rose to meet Moravcik's corner in the box, but he glanced his header wide of the post.

But Douglas almost cost his side in the 57th minute when he made a meal of Sutton's long-range shot which he could only parry into the path of Larsson, but luckily for the keeper, Wilkie made a timely interception to spare his blushes.

Despite their frustration Celtic refused to lie down and in the 61st minute their perseverance was rewarded when Moravcik swung the ball to Petrov unmarked at the back post and the Bulgarian headed down passed Douglas.

Dundee knew they had to go for a goal now and just two minutes later Gould almost surrendered their lead when he made a hash of Bonetti's free-kick, but he was grateful to collect at the second attempt.

But Wilkie was fortunate in the 66th minute not receive a yellow if not a red card after wrestling Sutton to the ground after a long hopeful ball down field by Gould and the striker was bemused as the referee adjudged the striker to be the offender.

The defender, however, did earn himself a booking moments later for a foul on Moravcik and then Petrov quickly followed him into the referee's notebook with a bad tackle on Bonetti.

But Douglas almost cost his side in the 57th minute when he made a meal of Sutton's long-range shot which he could only parry into the path of Larsson, but luckily for the keeper, Wilkie made a timely interception to spare his blushes.

Dundee tried their hardest to pull back the equaliser and threw everything at Celtic in the closing minutes, but Celtic dug deep to grab a hard-earned victory.