While Juve who have not conceded a goal so far this season won their third league game in a row title rivals and defending champions AC Milan slipped up with a surprise 2-1 defeat at home to newly-promoted Messina.
Roma came from behind twice to salvage a point in a 2-2 draw against Lecce at the Olympic stadium where their captain Francesco Totti saw his first-half penalty saved while Inter Milan won for the first time Adriano's late strike securing a 3-2 win at Atalanta.
Lazio moved up to second after winning 2-0 at Brescia while Cagliari won by the same scoreline at home to Siena.
Calabrian side Reggina won 2-1 at home to newly-promoted Livorno and Parma lost the Emilia Romagna derby going down 2-1 at home to Bologna.
Elsewhere there were goalless draws in the games between Chievo and Udinese and Palermo and Fiorentina.
Juventus coach Fabio Capello refused to get carried away with his team's scintillating start to the new campaign.
"This is a good result and nothing more he said. "We've beaten a good team who fought hard.
"We're happy to have won our second away game of the season and this run of results will boost our confidence.
"We have shown that we are a robust and compact squad that knows how to battle and overcome moments of difficulty."
Milan coach Carlo Ancelotti whose side have taken just four points from a possible nine admitted plucky Messina wanted victory more than his star-studded team.
"We came up against a determined and decisive team that played well for the whole 90 minutes he said.
"We haven't forgotten how to play but we must be more careful. Over the next few days we will try and evaluate what the problem is. It's nothing serious but we have to pick up more points."
Alessandro Del Piero gave Juve an 18th minute lead in Genoa slotting home a penalty after Samp defender Giulio Falcone hauled down Brazilian midfielder Emerson in the box.
Del Piero then made way for Zlatan Ibrahimovic in the 62nd minute and seven minutes later the Swedish international netted his second league goal firing a low angled shot in off the post after Pavel Nedved had carved open the home defence.
French striker David Trezeguet wrapped up the three points with a fierce low drive three minutes from the end.
Sampdoria have lost all three of their matches.
Defending champions Milan took the lead before being humbled by Sicilian side Messina at the San Siro.
Giuseppe Pancaro headed Milan in front in the 54th minute only for Domenica Giampa to level the scores 60 second later with a cool finish.
Riccardo Zampagna scorer of the winning goal in the 4-3 win against Roma on Sunday was again the star his superb diving header clinching a memorable victory for a team that has been absent from the top flight for nearly 40 years.
Messina's win lifted them up to third behind Lazio on goal difference.
Roma failed to lift the gloom hanging over them following the punishment handed out to them by UEFA on Tuesday.
European football's governing body awarded last Wednesday's abandoned Champions League match at home to Dynamo Kiev to the Ukranians after the referee was struck by a missile thrown from the crowd at the Olympic stadium.
The decision appeared to weigh heavily on Roma's shoulders and they were lucky to escape with a point against unbeaten Lecce.
Inter had Adriano to thank for three points in Bergamo but his long-range strike should have been held by hapless Atalanta keeper Massimo Taibi.