His first competition at the Langhorne (Pennsylvania) Track saw a 14th place finish in a 45 car field. In his third appearance at Heidelberg, Pennsylvania, a half mile dirt track, he showed outstanding potential by placing third behind winner Lee Petty and Dick Linder in a 100 mile, 22 car field. Rexford wound up 12th in the final point standings with two top five performances and Red Byron emerged as the first point champion.
In 1950, Rexford competed in 17 races and drove a 1950 Olds 88 supplied by Findley Lake car dealer Julian Buesink. His lone victory came on May 30 in a 200 lap dirt track event at Canfield, Ohio, where he defeated such drivers as Petty, Bill Blair and Tim Flock. In the first ever Southern 500 at the new superspeedway at Darlington, South Carolina, Rexford finished fourth among 75 drivers as he showed his skills on pavement. Finishing ahead of Rexford were winner Johnny Mantz, Fireball Roberts and Byron. Later that year at the banked oil Winchester, Indiana, layout he finished third with Jamestown area resident Lloyd Moore taking first place in a Buesink car. On the way to becoming the youngest NASCAR champion at 23, Rexford had five top five performances and 11 in the top 10 en route to 1,959 points and won $6,175.00. Rexford also became the only Winston Cup Grand champion from New York State.
Rexford competed in only 11 National events in 1951 and won the pole position at Canfield on May 30. It was the race he won in 1950, but this time around he was involved in a crash. He lost control of his car and went over the guard rails and sustained minor chest injuries. This accident had a lot to do with the end of Rexford's Grand National career. He entered only four more Grand National events and his final NASCAR race was July 1953 in Rochester where he wound up fifth in a 100 miler. Rexford made 36 Grand National starts with eight finishes in the top five and 17 within the top 10. His career winnings were $7,700.00. In addition, he was presented a Bulova watch courtesy of Illustrated Speedway News and a Nash Rambler Convertible for claiming the title. Rexford got into trouble with NASCAR by competing in some non-organization events. That got him expelled and fined $1,000 by NASCAR at one point.
After leaving NASCAR, Rexford joined the Midwest Auto Racing Club of Toledo, Ohio, for three years. He was sixth in his first year with MARC, the forerunners to the ARCA, and stayed inside the top 10 the next two years. He drove for several car owners (each operated auto dealerships) and shortly after he had completed his first two rides his replacements were killed. Those deaths along with other factors changed his viewpoint and he decided to give up racing. Rexford and his wife, Peggy, moved to Parker, Arizona, and started a trucking business there for around 25 years, then, relocated to Hemet, California. Rexford's love affair with racing was rekindled in 1987 when he and his wife attended a NASCAR racing show in Atlanta. For each championship driver on hand, the officials there attempted to secure on loan the car that each championship driver had ridden to glory. There was no Olds 88 available, so, the Rexfords toured in a Hudson. Rexford was again in the limelight when he was interviewed by TNN at the Phoenix International Speedway.
After several months of illness, Rexford passed away on March 18, 1994. Due to his illness, he was prevented from attending his selection into the New York State Auto Racing Hall of Fame in Buffalo. Rexford was also inducted into the Friends of Auto Racing Hall of Fame in 1995. He has been known as NASCAR's forgotten champion, but had the privilege of being featured on three different racing trading cards.