Celtic were handed a reality check last night when Ajax made amends for their abysmal performance a fortnight ago with an excellent display against the Scottish champions here at Parkhead.

Martin O'Neill's team were brought back to earth in no uncertain terms despite their progress to the Champions League proper.

At the start Celtic basically took over where they left off in Amsterdam and, indeed could have scored twice in the first two minutes as Steve Guppy sent over tantalising crosses that were met unsuccessfully first by Joos Valgaeren and then Henrik Larsson.

Yet after that the home team lacked conviction and Ajax, sensing their hesitation, took control of the first half. They softened Celtic up with a series of fouls that clearly unsettled the Scots and during that exercise Abuhakari Yakubu was booked for a bad challenge on Larsson.

The ploy worked from their perspective, however, and as they began to dominate proceedings they should really have opened the scoring after 20 minutes when Wamberto took advantage of a deflection off Paul Lambert to home in on Robert Douglas. The goalkeeper, though, was equal to the challenge and deflected the midfielder's close-range effort for a corner.

That was a hint of things to come but Celtic failed to heed the warning. Ten minutes later they again allowed Wamberto time and space, to their cost. This time the Brazilian played a slick one-two with Shota Arveladze and Wamberto's finish beyond Douglas was coolness personified.

Strangely that goal, and even manager O'Neill's exhortations from the touchline, failed to shake Celtic out of their lethargy and Douglas was forced into a fine diving save to divert a fierce Arveladze shot soon after.

It was not quite going according to plan for the huge home support at that stage and their nervousness was matched by their team, who could find no spark or rhythm and spent long, frustrating periods of the half trying simply to get the ball off the Dutch players. When they did, they found little or no space at all. In any case, Ajax were not reluctant to throw their weight about, as Paul Lambert discovered shortly before the interval when he was unceremoniously dumped by Rafael van der Vaart, who was immediately booked.

The anxiety among the home support remained almost tangible after half-time and Ajax did little to calm nerves with a good start during which Yakuba fired in a swerving shot that Douglas held comfortably.

It was all enough to set O'Neill on edge as well, however, and he looked a good deal less than pleased with his team's efforts the longer the game went on.

Yet the Dutch still had it all to do and with that in mind sent on Zlatan Ibrahimovic for Nikos Machlas after 65 minutes, closely followed by Richard Knopper for Ferdi Vierklau. The Celtic response was to send Lubo Moravcik into the fray in place of Jackie McNamara.

It became a little tense after that and Larsson and Christian Chivu had a minor altercation before Ajax sent on their final substitute Achmed Hossan, for Andre Bergdolmo. The changes favoured Ajax and Douglas was called into action again to make a good save from Ibrahimovic.

A flare among the Ajax fans was causing concern and police clashed with a small number of Dutch fans. But nothing could ruin the Celtic celebrations at the end.

CELTIC: Douglas, Mjallby, Boyd, Valgaeren, Agathe, Lennon, Lambert, McNamara (Moravcik 72), Guppy, Larsson, Sutton. Subs Not Used: Kharine, Sylla, Tebily, Petrov, Crainey.

AJAX: Grim, Chivu, Trabelsi, Vierklau (Knopper 72), Bergdolmo (Mido 76), Maxwell, Wamberto, Yakubu, van der Vaart, Machlas (Ibrahimovic 65), Arveladze. Subs Not Used: Stekelenburg, Heitinga, Pienarr. Booked: Yakubu, van der Vaart, Mido. Goals: Wamberto 30.

Referee: Stefano Braschi (Prato).