The Argentine striker scored in his Serie A debut to give the defending champions all three points.
The striker — who joined from Manchester City earlier this summer — found the net just before the hour mark to give Juventus all three points at the Stadio Luigi Ferraris.
Antonio Conte handed a league debut to Tevez, with the Argentine partnering with Mirko Vucinic in attack, while Paul Pogba started in midfield in the absence of Claudio Marchisio.
Juventus came close to taking the lead after just two minutes, when Andrea Pirlo's superb long-range strike was tipped over the bar by Brazilian goalkeeper Angelo Da Costa.
Sampdoria responded well, pressing Conte's men back into their own half. But they could not take advantage of that period of supremacy and almost fell behind when Da Costa produced another fine save as Kwadwo Asamoah met a Pirlo corner with a powerful diving header.
The visitors' attacking quality was evident, and Sampdoria was again grateful for the reflexes of Da Costa as he denied Tevez his first goal in Italian football with a great stop at the near post.
Asamoah fired a swerving effort over the bar from the edge of the area seven minutes before the interval. But despite an array of chances, the Bianconeri were left frustrated as they failed to find a breakthrough before halftime.
But in the 57th minute, the visitors sprung back to life in spectacular fashion. Vucinic, Arturo Vidal and Pogba combined in a wonderful team move, with the latter pulling back for Tevez to tap into an empty net with Da Costa stranded.
The hosts nearly crafted an instant response, however, as defender Andrea Costa converted from an in-swinging free kick, only for the assistant referee to disallow the goal for offside.
Pogba, afforded too much time and space by Sampdoria, continued to exert his influence on the game, and he was heavily involved again as Juventus looked to close the match out, crossing for Stephan Lichtsteiner, whose header went wide.
Juventus took its foot off the gas late, with Sampdoria lacking the ability to equalize. And the game ended on a sour note for the hosts, with substitute Paolo Castellini sent off for a lunging tackle on Lichtsteiner to extinguish any hope of a late comeback.