Police in Patong believe the man would have raped the 23-year-old Aussie tourist if he had succeeded in getting her into his Toyota Vigo pickup.
The woman's desperate cries for help brought bellboy Panpong Srisamai from the Nap Resort and Piyanutsara Perhat, who was nearby, close to Patong's beach road, at 4am.
But it was the physical intervention of Japanese tourist Takahiro Maruyama, 26, that prevented the woman from being abducted.
Mr Maruyama suffered a cut that later needed stitches and a black eye, police said, but he and the others managed to subdue the woman's attacker and hold him until police arrived.
Police at Kathu station, which oversees Patong, were holding Kagornsak Rungrang, of Ranong, for attempted rape.
Officers said Khun Kagornsak saw the Australian tourist out walking alone at 4am and decided to pounce.
Management at The Nap said today that Mr Maruyama was resting after treatment at Patong Hospital. He planned to leave Phuket tomorrow, as scheduled.
Today's attack took place in a poorly lit part of Patong, near a construction site, where there are no security cameras.
The incident follows rising concern about violence committed on tourists on Phuket and the ''cry rape'' case last month of Australian tourist Stevie Bamford who lied about being attacked by a tuk-tuk driver for fear her boyfriend would react angrily when she stayed out late.