A controlled Chelsea side came of age in Rome as they withstood a fierce onslaught from the most expensive club side in the world to keep their Champions League dream on course.

Lazio manager Sven-Goran Eriksson called upon the striking expertise of four proven stars - Simone Inzaghi, Roberto Mancini, Marcelo Salas and Alen Boksic - but none were able to penetrate a supremely-disciplined Chelsea side. If they played like this every week, the Premiership would be a doddle.

Eriksson's reasons for buying a fifth striker, Fabrizio Ravanelli, this week are more through necessity than extravagance.

The only black spot on a night of Italian theatre at its most compelling was the second-half sending-off of Gianluca Vialli, who last came to the Stadio Olimpico as a Juventus player to pick up the European Cup trophy.

Though this result keeps the same outcome on course, it was a personal disaster for the magnanimous manager. Before the game, he expressed doubts about his own ability to do his job, and after Flo was punished after 58 minutes for raising an arm, he expressed similar doubts about German referee Helmut Krug.

Swearing at a linesman was the official reason for Vialli's subsequent bizarre dismissal but the interlude seemed to galvanise his side further - and the reason why Eriksson took the liberty of bringing Salas and Boksic off the substitutes' bench.

The Chilean almost made an impact when he was allowed room to turn on the penalty spot, but he scuffed his shot in a moment that belied his international record of 30 goals in 44 appearances.

Seconds earlier, Zola had illuminated the stadium with a piece of cheek you wouldn't expect from a fluorescently-bejewelled red-haired wild child out after hours. Culminating a delightful move that Ferrer began in his own area, via Leboeuf, Deschamps and Flo, the diminutive Sardinian turned two defenders before chipping Marchegiani.

The keeper was beaten, but the post was not. Babayaro was following up but halted as the ball looked to drop inexorably inside the post. It clipped the upright, Babayaro was wrong-footed, and the danger was over.

Lazio's most influential substitute was Sergio Conceicao, who knocked in two dangerous crosses which Boksic failed to capitalise on. In the final minute, the Croatian flashed a drive over the bar that would have undone all the hard work.

Perhaps this result was no surprise after all. The similarities between the two clubs, as Simon Kuper pointed out in The Observer, were clear from the start - and not just because "both blue-shirted under-achievers from their country's capital" qualified for this competition in the 'non-champion' category. Both have only won their domestic league once (Lazio in 1974, Chelsea in 1955); both have the extravagance of their wealthy chairmen to thank for their current situation.

And both, of course, not so long ago fielded an Englishman in their side. But where Paul Gascoigne was missing in the Lazio midfield was the impressive Argentinian partnership of Veron, who cost a nifty 18m from Parma, and Simeone.

And Veron was looking cheap at the price. In a cat-and-mouse first half, it was he who looked most likely to unlock the Chelsea defence, constantly creating time on the ball and unleashing his exquisite range of passing.

As Simeone and Nedved cancelled out Wise and Deschamps, it was left to Veron and Roberto Mancini to threaten Ed de Goey's goal. But for all their possession in the final third, the Chelsea defence - marshalled superbly by Marcel Desailly - that collapsed against Sunderland was standing firm.

Mancini put his friendship with Vialli, with whom he combined to form the Terrible Twin partnership that brought Sampdoria success in the 1980s, on the line when his delicate chip from the right beat the offside trap to release Simone Inzaghi, but the louche lothario had his effort smothered well by de Goey.

It was the only clear-cut chance of a half that saw Nedved ping a 25-yarder just wide, Simeone blast a hopeful long-shot over the top and Inzaghi fail to connect to two more sharp through-balls.

Veron continued to impress after the break, and came even closer when his inswinging corner clipped the top of Lombardo's shiny pate and thundered against the post. Had the Italian international midfielder a bit more on top, it might have been a different story.

Lazio dominated the corner count (14-1) and had some free-kicks in dangerous areas. But they were missing the suspended dead-ball specialist Sinisa Mihajlovic (as well as Giuseppe Pancaro and Dejan Stankovic) and that counted in Chelsea's favour.

But for all the guile on display, for all the millions they cost, for all the pre-match bravado they uttered, Lazio could not manage what three days earlier Kevin Phillips and Niall Quinn both did twice. One goal.

The Italians, men with 'Del Monte' emblazoned across their chests, kept on saying 'Yes', but de Goey, and the heroic Chelsea back line, which began with the tireless Flo and Zola, responded again and again: 'No.'

Chelsea's next European adventure is not until February - which gives them ten long weeks to revel in their status as top of a very tough group. Then the really hard work begins.

Lazio: Marchegiani, Gottardi, Favalli, Couto, Nesta, Simeone, Lombardo (Boksic 69), Veron, Nedved, Inzaghi (Salas 46), Mancini (Conceicao 79).
Subs Not Used: Ballotta, Marcolin, Sensini, Pinzi.

Chelsea: De Goey, Ferrer, Babayaro, Leboeuf, Desailly, Poyet, Wise, Deschamps (Di Matteo 75), Petrescu, Zola, Flo.
Subs Not Used: Cudicini, Hogh, Sutton, Goldbaek, Morris, Lambourde.
Booked: Ferrer.
Att: 64,500