At the 1964 U.S. Championships later that summer, Belkin defeated Rodney Susman in the first round before falling to Cliff Richey in the second in five sets.

Belkin won the Detroit Invitation, a strong field tournament, in early July 1965, defeating the USTA No.

He defeated Australian Jim Moore in straight sets before falling to that year's eventual champion, Manuel Santana.

In July 1966 Belkin won the Quebec Open, defeating seven-time winner of the event Robert Bédard in the marathon five-set final.

In early July 1967, Belkin won the Detroit Invitation tournament for the second time, defeating Ron Holmberg in the semifinal and Chuck McKinley in the final.

Belkin won the ILTF Western Championships in Indianapolis on clay in July 1967, defeating twice-defending champion and USTA No.

Belkin also defeated Richey in the quarterfinal of the U.S. Men's Clay Court Championships in Milwaukee, but lost to Marty Riessen in the semifinal.

[7] Belkin won the 1968 ILTF St. Petersburg Masters Invitational on clay in April, defeating Mike Sangster in the quarterfinal, Bowrey in the semifinal, and Jaime Fillol in the final.

Belkin played the 1969 French Open, but was forced to abandon his match against Georges Goven despite leading by two sets.

In the summer, Belkin played the Cincinnati Championships, defeating Phil Dent and Stan Smith in the later rounds to reach the semi-finals.

Two weeks later, Belkin played the Canadian Open, reaching the semis in singles, where he lost a four-setter to the eventual champion Richey and the quarters in doubles, partnering compatriot Vic Rollins.

The following week in Indianapolis, he defeated Jean-Baptiste Chanfreau and G. Turner Howard before losing in three sets to Croat Željko Franulović.

In mid-February he played the New York Grand Prix, losing in the first round in singles, to Manuel Orantes and doubles, partnering Richard Russell.

In doubles, he and partner Nikola Špear won two matches to reach the quarter-finals, where they lost to Kodeš and Željko Franulović.

In April, Belkin won the ILTF St. Petersburg Masters Invitational on clay for a second time, defeating Harald Elschenbroich in the final.

One week later Belkin reached the third round of the Cincinnati Outdoor, beating Rudy Hernando and Brian Gottfried before succumbing to Jaime Fillol.

The following week Belkin competed at the Canadian Open, losing in the first round in singles to Ray Ruffels, and in doubles partnering once again John Sharpe.

In early February, he lost handily in singles in the first round in Omaha and Kansas City in consecutive weeks, both times to Ilie Năstase.

Two weeks later, Belkin reached the second round in singles in Salisbury, defeating Milan Holeček before falling to Roscoe Tanner.

Belkin was entered one more main draw, in mid-September, the Montreal WCT, but withdraw from his first round match in both singles and doubles (partnering compatriot Richard Legendre).

He lost in the first round to Herb Fitzgibbon in singles and in doubles partnering Nicholas Kalogeropoulos at the Baltimore Indoor in early January.

Two weeks later at the Birmingham Indoor, Belkin reached the second round in singles, beating Szabolcs Baranyi before losing to Jürgen Fassbender.

Belkin won the 1973 Buffalo Indoor Tennis Championships[8] in February, defeating Clark Graebner, a four-time champion at the event, in the semifinal and John Paish in the close final.

In middle February, at the Calgary Indoor, Belkin defeated Hans Kary in three sets before falling to Paul Gerken.

In doubles, he and partner, veteran Quebecer Robert Bédard, lost in the first round to Onny Parun and Raymond Moore.

Two weeks later at the Boca Raton Grand Prix he completed his touring career with his best result in years, reaching the quarter-finals.

The following year Belkin defeated Mike Sangster in the opening rubber against Great Britain in Europe Group first round action, played in Bournemouth on clay.

Britain won the next four rubbers however, including the doubles 12–10 in the fifth, with Roger Taylor and Bobby Wilson overcoming Belkin and Keith Carpenter.

Belkin concluded his Davis Cup career retiring from rubber 1 against Iván Molina of Colombia, having lost the first set 7–9.

Belkin's career Davis Cup win-loss stands at 14 and 7 in singles and 3 and 5 in doubles, with all matches played outdoors on clay.