Juventus moved up to 73 points with nine games to play when Cuadrado, making his 50th appearance for the reigning champions, met Kwadwo Asamoah's excellent cross from the left in the seventh minute with a diving header to give Massimiliano Allegri's relentless league leaders an early lead.
Sampdoria came out battling after the break, and came close to equalising when the outstanding Asamoah was forced to deny Patrik Schnick with an exceptional last-gasp interception, but Juve defended stoutly to see out the win.
Earlier, Napoli consolidated their grip on the Champions League places and moved 10 points behind Juve and provisionally above Roma into second on 63 points with an exhilarating win at Empoli.
Maurizio Sarri's side blew away his former club during the first half and were 3-0 up after a double from Lorenzo Insigne and Dries Mertens's free kick inside the opening 38 minutes, with the latter also having an early penalty saved.
Read the full article on eurosport.co.uk: Juventus beat Sampdoria as Scudetto draws closer