Manchester City's Aleksandar Kolarov rescues a point against Napoli

Aleksandar Kolarov, right, celebrates with Sergio Agüero after scoring against Napoli in the Champions League. Photograph: Scott Heavey/Getty Images

The challenge of the Champions League had been anticipated for the past few years at Manchester City, but a grand occasion can also be a trial. Having gone behind to Napoli in the 69th minute, there was at least an expert reaction when Aleksandar Kolarov's free-kick sent the ball snaking low into the net six minutes later. Expectations at the club will still have to be reconsidered.

With all the talk of City's first European Cup match since 1968 there was almost an insinuation that a club of such means would make a spectacular reappearance in the tournament. It was not quite so simple as all. Roberto Mancini's players certainly started as if they could not be checked, but any such assumption was disrespectful to a Serie A side that did not crumple when forced back.

There was no obvious reason why the hosts should have looked a touch uneasy on occasion. City as may lack experience in this competition in modern times, but their squad is crammed with men of know-how and achievement.

While they have the sort of means that might deliver instant authority in the tournament, there are still challenges to be confronted by both Roberto Mancini and his players. The ability in the ranks is beyond dispute, but this manager knows that the vivacious football he has gradually introduced will not in itself be enough establish him completely.

While City are now playing with more enterprise there could have been a counterbalancing sense that rashness was unnecessary in what was simply the opener in the six group fixtures. Mancini, for that matter, would have regarded the fixtures to come with caution. But everyone could see before half-time that a touch of wariness was not helping their cause.

Napoli had quaked in some early exchanges, but professionalism saw them through that period and they appeared to be enjoying the occasion more than City. That was perhaps to be expected. The home team realises how much expectation it has to bear. City could still have had the lead before the interval. Yaya Touré tore forward in the 34th minute and linked with Sergio Agüero before shooting against the bar. Three cautions for Napoli before the interval also spoke of their discomfort.

Despite the quality in the City ranks, they had to be patient and trust that the yellow cards were a sign of the opposition losing its capacity to compete legitimately. In the depths of their hearts, though, City fans would have envisaged a spectacle to confirm that the club's standards are the equal of the elite. Those of a more philosophical turn of mind could have argued that the whole point of City's rise has been to play for high stakes and feel the tension.

There was no cause for any fan to be irate and the mood was still a positive one. The wonder of witnessing a fixture of this sort in the ground left a residual thankfulness. Nonetheless, City were under a certain stress. That, after all, is normal for the prominent teams. There might have been an opener for them in the 40th minute, but the goalkeeper Morgan De Sanctis reached an Kolarov drive aimed for the corner of the target. Nothing so very terrible had happened to City and the main priority would have been to stay calm and methodical.

Mancini's players was to be tested here, especially when a deep cross from the left fell to Marek Hamsik and the Slovak's drive needed to be cleared expertly from the goal-line by Vincent Kompany in the 50th minute. There were several moments when those who have made too much of the relative decline in Serie A had to appreciate the potency these clubs can find.

Indeed the Champions League ought to be distinguished by this sort of challenge from the visitors. With an hour gone, there did seem to be territorial progress by City, buy it did not evolve into any sort of onslaught by the home side. Mancini, in any case, would have been against any recklessness when the group has barely started.

This had turned into a game where defeat for City became more easy to envisage as the minutes passed. When Napoli opened the scoring in the 69th minute, the opportunity arose because Gareth Barry lost possession in midfield by attempting a backheel. Christian Maggio surged away with ball and Edinson Cavani converted the chance. Agüero was soon clipping the bar from a low delivery by Samir Nasri, but the Champions League had become a grave matter for City. Their firm reply at least showed resolve.