Stilian Petrov grabbed his second goal in two games to give Celtic victory at Parkhead today as the champions-elect clasped another finger around the Premier League title trophy.

The Bulgarian killed off any slim hopes that Rangers had of catching their arch rivals with a strike at Ibrox last week.

And Petrov delivered another quality goal today as the Glasgow giants moved to within just two victories of retaining the title and their first back-to-back championships in 20 years.

But the points were always on the cards from the moment referee Mike McCurry started the game with Alex Smith's negative side mustering just one shot on target in the whole of the game.

The home crowd also sensed Celtic would take the points from the game when they arrived and the rare appearance of the sun added to the carnival atmosphere at Parkhead.

The only surprise was that it took so long for them to break the deadlock as United planned to frustrate them by defending in numbers.

United skipper Danny Griffin needed to be alert in the third minute to cut out Didier Agathe's right-wing cross with Moravcik lurking ominously at the back post.

Moments later Celtic youngster Stephen Crainey could have enhanced his chances of being in Berti Vogts' first Scotland squad on Monday after almost putting his side in front.

Moravcik directed Agathe's cross across the face of goal and the outstretched boot of the defender diverted the ball just wide.

Celtic needed to be patient against United's defensive tactics, but Paul Lambert, who announced his international U-turn this week, led by example with a typically inspiring display.

But the midfielder was in the wars in the 11th minute when he was caught late by Hasney Aljofree.

The crowd though and Vogts, who will have him in his squad for the friendly with France, were relieved as he returned to action after some treatment while the United man was deservedly booked.

Celtic continued to probe and they carved out another half chance in the 13th minute.

Agathe crossed to the far post after leaving Aljofree in his wake, but the ball was just too high for Moravcik and he could only head over the crossbar.

Lennon drove a right-foot shot wide from 22 yards before United keeper Gallacher saved his side in the 23rd minute.

Larsson peeled off his marker and got on the end of Steve Guppy's corner, but the youngster showed great agility to touch the Swedish star's header over the bar.

While United were defending resolutely their attacking play failed to match the brightness of their glaring orange shirts.

But Moravcik and Agathe had the ability to light up even the dullest of games and the duo combined on the half-hour which nearly produced the reward the move deserved.

The Slovakian's quick feet shook off the attentions of Venetis and he sent the Frenchman away with a superb reverse ball. Agathe outstripped Jim Lauchlan for pace, but Larsson was just unable to get on the end of his right-foot cross.

Lennon became the second man booked in the 33rd minute for a foul on Steven Thompson and it brought United's first shot on goal, but Robert Douglas comfortably saved Griffin's free-kick.

Petrov squandered a good chance in the 40th minute. The midfielder took his eye off the ball in the area after the United defence had failed to clear Agathe's cross and he completely missed the ball with his swinging leg.

But the Bulgarian made amends just seconds later by scoring the opener when he brilliantly exchanged pass with Larsson on the edge of the area before coolly slotting the ball past Gallacher.

Despite being a goal down and Celtic being without key stars, United refused to commit more men forward.

In fact it was the home side who continued to threaten after the break and they opened the United defence at will in the 48th minute with a quality passing move.

Crainey exchanged passes with Larsson and pulled his cross back from the byline, but Petrov was just inches away from scoring his second of the game and killing off the visitors.

Petrov almost scored again in the 65th minute when he latched on to a poor clearance by McCracken, but his volley was comfortably saved by Gallacher in the United goal.

Substitute Jamie Smith replaced Moravcik in the 73rd minute and the youngster almost sealed the points minutes later.

He took Lambert's pass in his stride before crashing a fierce right-foot shot against the underside of the bar.

As the minutes ticked down Larsson headed Guppy's corner over the bar, but even at 1-0 the game was over and the crowd and players showed no signs of any nerves.

And with a 13-point lead over Rangers - why should they?

Teams

Celtic: Douglas, Mjallby, Boyd, Crainey, Agathe, Lennon, Lambert, Petrov, Guppy, Moravcik (Smith 72), Larsson.

Subs Not Used: Gould, Sylla, McNamara, Tebily.

Booked: Lennon.

Goals: Petrov 41.

Dundee Utd: Gallacher, McCunnie, Lauchlan, Griffin, McCracken, Duff (Paterson 67), Venetis (Lilley 81), Easton, Aljofree, Miller, Thompson (Winters 86).

Subs Not Used: Jarvie, Cocozza.

Booked: Aljofree, Miller, McCunnie.

Att: 58,392

Ref: M McCurry (Scotland).