Celtic kept their Champions League ambitions firmly on course with another outstanding home performance against Rosenborg. With the overnight group leaders Juventus held 0-0 by Porto last night, Martin O'Neill's men moved a point clear of the Italians at the head of their group.

The Scottish champions displayed all the qualities that sent Porto back to Portugal pointless a couple of weeks ago, and once again this result and performance from the group's outsiders will reverberate around Europe.

The victory came courtesy of a well-taken free-kick by Alan Thompson and few could deny that Celtic were worthy winners of this latest challenge.

Now the Glasgow team are well placed to reach the second phase of the tournament.

With so much at stake, it was hardly surprising both teams decided that attack was the best form of defence from the start.

Celtic, backed as ever by a huge crowd, set the early pace with a series of lightning raids, one ending only when the Rosenborg captain Erik Hoftun came to the rescue by hacking clear a dangerous cross-cum-shot by Didier Agathe.

Yet the Norwegians were always keen to exploit the pace of the former Celtic forward Harald Brattbakk and they looked threatening more than once on the break.

However, generally speaking, it was Celtic who enjoyed more of the decent possession and, although they had a half-hearted penalty appeal for hand ball against Orjan Berg turned down after 13 minutes, they had to wait only another seven before taking the lead.

The problems for Rosenborg were of their own making as Janne Saarinen brought down Stilian Petrov as the Bulgarian tried to burst into the penalty area.

The indiscretion cost the defender a booking and his team a goal as Henrik Larsson left the free-kick to Alan Thompson who drove a low shot through a crumbling wall and past Arni Arason.

It was precisely the breakthrough Celtic wanted and it turned the stadium into a cauldron as the noise level was raised by a number of decibels.

Celtic emerged for the second period in much the same mood and maintained their momentum to such effect that they came close to adding that precious second goal after just five minutes.

Sutton sent Larsson scampering on his way through the middle but the combined efforts of Arason and Hoftun eventually proved too much for the Swede.

After 63 minutes, the home team should probably have gone further ahead when Thompson's free-kick was touched on by Sutton to Larsson, who normally scores for fun from such close range but had to watch Arason block well on this occasion.

The Celtic manager then decided on a change, although the substitution of Thompson with Steve Guppy was little more than a straight swap after 65 minutes.

Two minutes later the Scots had a second penalty appeal rejected after a challenge by Ole Basma on Sutton although, like the first, it would have been harsh on the visitors had it been awarded.

Indeed, Rosenborg needed a switch of their own to try and break Celtic's stranglehold and that came when Christer George replaced Brattbakk after 73 minutes although, even then, the next opportunity fell to the home team when Arason did brilliantly to block Sutton's deflected drive.

CELTIC: Douglas, Balde, Mjallby, Valgaeren, Agathe, Lambert, Lennon, Petrov, Thompson (Guppy 66), Larsson, Sutton. Subs Not Used: Kharine, Sylla, McNamara, Hartson, Tebily, Moravcik. Goals: Thompson 21.

ROSENBORG: Arason, Saarinen, Johnson, Basma, Hoftun, Olsen (Frode Johnsen 86), Strand (Winsnes 82), Berg, Skammelsrud, Brattbakk (George 74), Rushfeldt. Subs Not Used: Espen Johnsen, Stensaas, El Fakiri. Booked: Saarinen.

Referee: A Sars (France).