Both Inter Milan and AS Roma also suffered humiliating away defeats Sunday, respectively at the hands of Udinese and Napoli, reports Xinhua.
Juventus dominated the match in the beginning as Sebastian Giovinco's early penalty put them ahead before Sampdoria's Gaetano Berardi saw red for two first-half bookings.
But the numerical advantage did little to help the hosts, as Mauro Icardi levelled the score shortly after the break.
Icardi completed his brace with what proved to be the winner, his sensational strike rattling the Bianconeri to condemn them to a second home defeat of the season, also earning Delio Rossi a first victory as Sampdoria boss.
Juventus now lead the second-placed Lazio by just five points ahead of a daunting trip to Parma.
Roma were thrashed by Napoli 1-4 in a one-sided game where Edison Cavani completed his hat-trick at the 70th minute to put the hosts 3-0 up. Pablo Daniel Osvaldo grabbed one back for Roma three minutes later before Christian Maggio scored Napoli's fourth goal in the 90th minute.
Udinese scored three goals in the second half to beat 10-man Inter 3-0.
