After the successful hernia operation in November 1977, Mazzetti got back in shape by returning to São Paulo, Brazil and working out with a semi-professional soccer team in the winter of 1977–78 and returned to Philadelphia in time to attend the open tryouts for the Philadelphia Eagles and the New York Jets. He was invited to go to training camps for both teams, and decided on the Eagles. Mazzetti made it through the entire training camp that summer of 1978, but was released in the last cut when head coach Dick Vermeil decided to go with his veteran, Nick Mike-Mayer. Mazzetti then was invited to single-day tryouts once the 1978 season began for the Dallas Cowboys but lost out to Rafael Septién and the New Orleans Saints. Still unsigned, Mazzetti settled for a $50 a night job as a bartender at Smokey Joe's near the University of Pennsylvania campus. Six games into the season, Mazzetti signed with the Atlanta Falcons. Mazzetti had a cinderella season that first year with Atlanta, making 13 of 16 FGs, including a team record 11 in a row, as well as kicking 4 game-winning FGs. In a memorable Monday-night game against the division leading Los Angeles Rams on October 30, 1978, Tim Mazzetti went 5-for-5 and the Falcons won 15–7. During the game, Howard Cosell exclaimed, "This Philadelphia bartender won't need to mix scotch-and-waters any longer." As a result of Mazzetti's heroics, the Falcons made it into the playoffs for the first time ever in the franchise's history as a wild-card, and in their first-ever post-season game against the Philadelphia Eagles, Mazzetti's former employer, he provided the point differential in a 14–13 game. Mazzetti remained with the Falcons through the 1980 season, but was cut by the team near the end of its 1981 training camp.