Manchester City's manager Roberto Mancini is a master once more but Andre Villas-Boas exerts callow authority

The search for eternal youth has engaged the vainglorious across the sweep of time. In football managers it is not a convincing attribute. The longer this game went on the younger Andre Villas-Boas appeared. The heavy clump of adolescent hair coupled with his padded jacket and tie conferred all the authority of a sixth former on lunch duty, plausibly filling time but to no great effect.

A couple of metres to his left, the greying Roberto Mancini looked a man in control. The introduction of Edin Dzeko with 18 minutes remaining proving his omniscience yet again. It has not gone his way in the Champions League but in this division against opposition a class below the likes of Real Madrid, Borussia Dortmund and Ajax, Mancini is master of his manor.

AVB in contrast finds himself on inverted ground, contesting a European campaign that at this stage of the season is not as demanding as a visit to the champions of England. Thursday's triumph against Maribor offered no protection from the negative interpretation attached to days like this, when Spurs were unable to hold on to an advantage they stole in a first half of modest plodding.

The performance of Steven Caulker, the excellent Sandro and a reconstituted Emmanuel Adebayor were all serious pluses for Spurs. What Villas-Boas needed was the Gareth Bale that ran through Internazioanle, and Aaron Lennon at his positive best. Lennon was a peripheral figure. When Dzeko came on for Carlos Tevez with the game already stretched he must have thought the player opposing him on the far side of the pitch an impersonator.

Mancini conjured from his game breakers – Sergio Aguero, Yaya Touré and David Silva – definitive improvements after the break. And when the moment arrived Dzeko delivered his riposte to bench duties, scoring his seventh goal of the season. His contribution changed not only the complexion of the afternoon but the narrative setting the week's agenda. Mancini is a tactical genius again, at least until the visit of Real next week. Villas-Boas must deal with the resurrection of the question mark above his head.

While Dzeko's headers were going astray and Silva was shooting narrowly wide Villas-Boas had a point on the road to help prop up his work. Defeats gather a momentum all their own. On his last visit to Manchester the coach was validated by a stirring first-half display. Spurs were on the back foot for the latter 45 minutes at Old Trafford but hung on. That was a good day. On days like this touchline tics are perceived differently, not as quirks but failings.

All that arm flailing at the close, the entreaties to the referee when Jermain Defoe went down in the box fell easily into the category marked "desperation". Here was a figure at the mercy of events not dictating them. The optimism that ballooned on the back of the win at Manchester United has dissipated with a fourth league defeat.

Spurs remain in the shake-up for fourth, a point ahead of north London neighbours Arsenal, where fate sends them next. Saturday's early kick-off at the Emirates acquires even greater significance with this reverse. Arsène Wenger could do with a result himself. What better way to restore faith in the project than putting one over the neighbours.

Villas-Boas retreated into coaching speak to account for the defeat, a favourite technique of his. "It was difficult because Manchester City's line was very high and they pushed us very well, so it was difficult to make that second pass in the link-up play. In the end, he [Adebayor] had a positive impact regarding the structure we put together. It's a pity we didn't get a result in the end."

Oh to be in front of a white board in the Spurs changing room. Sometimes it is better just to accept that you weren't good enough. No shame in that at the Etihad yesterday.