The first cracks in John Barnes' Celtic reign were recorded at Tannadice when his team fell to their first defeat and never recovered. Last night at the same venue, the latest boss to try to bring this club out of the darkness made sure that his men were not leaving with less than three points. Martin O'Neill stood and bullied a performance out of his team. He was never out of their sight, pointing, clenching fists and, ultimately, throwing his arms aloft in jubilation as Hugh Dallas' final whistle brought his competitive debut to a joyful conclusion. The fact that the winning goal was scored by the man he paid £6million to secure, Chris Sutton, only served to make victory sweeter. The former Chelsea man's nightmare at Stamford Bridge was banished with one instinctive stab of the boot in the 66th minute.

The goal restored Celtic's lead after young David McCracken had equalised Henrik Larssson's clinical first-half opener and it was no more than they deserved for a display that was patchy in parts but never lacked passion. Already, this team seems more prepared to fight for each other than the one inherited from Barnes. Instead of buckling when they lost the lead, they simply redoubled their efforts and got their reward. It simply has to be that way with the Irishman watching over their pass, every tackle. He's never been happy to accept second best and last night he served notice that he isn't about to start. Stephane Mahe might not have impressed his new boss too much by being involved in a training ground set-to with Vidar Riseth on Friday but the Frenchman was involved from the start last night while the Norwegian was nowhere to be seen. The same goes for Rafael. Joos Valgaeren's appearance meant no place for the Brazilian, who had the ignimony of seeing Olivier Tebily getting the nod for a place on the bench ahead of him.

Of course, United also made some personnel changes in the summer and as the evening sun broke through the clouds we got a first glimpse of Neil Heaney, Hasney Aljofree, and Jamie Buchan for the tangerines. Or the greens, as it was last night. The Tannadice outfit sported their new away colours even though they were at home. Ah, the power of TV. Celtic, too, wore their change kit but at least they were the away team. They brought with them a large and vocal following, but United's support did not fill their allocation and that must be a worry for Jim McLean. If they can't fill their seats on a lovely summer's night for the first game of the season against one of the Old Firm - even if it is on Sky - then what will their crowds be if the team is struggling halfway through the campaign? Jonathan Gould was the first keeper to get his gloves dirty but he dealt with David Hannah's 22-yard free kick easily enough. Celtic had the bulk of possession but United were working manfully to close them down. They paid too much attention to Alan Stubbs on the edge of the box in the ninth minute and had Combe to thank for staying on level terms. Larsson took the free-kick, bent it round the wall and would have been celebrating but for the athletic plunge to his left by Alan Combe. Berkovic took the corner, Valgaeren rose highest but again the keeper was equal to his effort. Valgaeren looked like something Celtic have lacked for too long - a commanding centre-half who does nothing fancy but does not induce heart-failure among team-mates. United were struggling to make a dent in the Celtic back three and new boy Heaney's frustration at being unable to get into the game manifested itself with an ugly lunge at Mahe which brought a booking.

Eyal Berkovic was probing and prompting but when Celtic finally did take the lead in 37 minutes it came through a more direct route. Sutton won the ball in midfield and surged to the edge of the area where Jason de Vos stuck out a long leg to win the ball. It broke to Larsson and the left leg that was snapped so horribly last October swept a wonderful effort low past Combe from 16 yards. O'Neill leapt like a jack-in-the box and hugged anyone within hugging distance. United would have been more pained by the loss of a second goal, however, and right on the break it almost came. Berkovic fed Stilian Petrov with a lovely ball but Combe bravely saved at his feet. United started the second period much more positively and got their reward after just four minutes. Jackie McNamara was adjudged to have committed a foul on Jim Paterson near the corner flag and when Heaney flighted the free- kick in, Gould ended up on the deck as the ball ended up in the net.

That Gould and Hannah had made contact was indisputable but referee Hugh Dallas felt the collision was accidental - and with the Celtic keeper out of commission young defender David McCracken had only to nod home from six yards. O'Neill would not have been happy with his keeper - and neither would watching Sheffield Wednesday boss Paul Jewell who was there to run the rule over him. Celtic hit back with a ferocity that almost took them straight back into the lead. Sutton had a header deflected on to the roof of the net, then he had the ball in the net - but provider Larsson had carried the ball over the byeline. At the other end, the impressive Paterson hit a great cross for Thompson but from just eight yards the striker feebly nodded into Gould's arms. Celtic threw on Tommy Johnson for Berkovic in the 64th minute. Two minutes later they were back in front. Combe saved a McNamara piledriver brilliantly but Mahe slammed the ball back across for Sutton to stab the ball over the line. Game over.

DUNDEE UTD : Combe, Hannah, de Vos, Easton (McConalogue 84), Mathie (Hamilton 78), Heaney (Venetis 71), Aljofree, Paterson, Thompson, Buchan, McCracken. Subs not used: Onstad, McQuillan.