During his rookie season, the Yanks became the Dallas Texans, which became the Baltimore Colts in 1953. Marchetti played 13 seasons with the Colts and helped them win NFL Championships in 1958 and 1959. During his career, he was noted for being effective against the run and a relentless pass-rusher. He was voted "the greatest defensive end in pro football history" by the Pro Football Hall of Fame in 1972.
He moved to left offensive tackle in 1954, a position Marchetti hated, but admitted that it taught him how to beat a blocker. He returned to defensive end in 1955 and made his first Pro Bowl.
He made a big play in the 1958 NFL Championship Game when he prevented the New York Giants from gaining a first down by tackling the running back just a yard before the first down mark. He fractured his ankle on that same play but, as a team captain, insisted on watching the rest of the historic overtime contest from the sideline with his teammates rather than seeking immediate medical attention in the locker room. The injury forced him to miss the Pro Bowl that year and ended his string of nine consecutive Pro Bowl appearances. Marchetti was First-team All-Pro nine times and a Second-team selection once.
Marchetti's stellar play led to his being called by Sid Gillman, the Los Angeles Ramshead coach, "(T)he greatest player in football. It's a waste of time to run around this guy's end. It's a lost play. You don't bother to try it."
Forrest Gregg in an interview: "You ask who was the best ... just my opinion, Marchetti was the best all-around player I ever played against. Great pass rusher. Great against the run. And he never let you rest."
In 1959, Marchetti joined with several of his teammates, including Alan Ameche, and opened a fast food restaurant. The business grew, began to franchise, and would eventually become known as Gino's Hamburgers. It was a successful East Coast regional fast food chain and had 313 company-owned locations when they were sold in 1982 to Marriott International, which abandoned the name in favor of their Roy Rogers restaurants.
In 2009, Marchetti teamed with other former key Gino's employees to resurrect the Gino's name. Hiring commenced in September 2010 to staff their first new restaurant in the company's old hometown of King of Prussia, Pennsylvania, and Gino's Burgers & Chicken, as the company is now known, opened its first store on October 25, 2010. This restaurant has since closed. The company is looking for locations throughout the Philadelphia area, and has restaurants in Glen Burnie, Maryland, Towson, Maryland, Aberdeen, Maryland, as well as at Camden Yards and Ravens' Stadium, in Baltimore, Maryland. 
*Tied for 1st place in their division, but since there was no tie-breaking system in 1965, a game was played to determine who went to the conference championship. The Colts lost the divisional playoff game.