French and European bantam champ

On 6 November 1953, Cohen defeated French bantamweight champion Maurice Sandeyron easily taking the title in a fifteen-round bout in Paris, having beaten Sandeyron earlier on 19 January in a ninth-round knockout in a non-title bout.^[4] A religious Jew, one source noted that he briefly attended a Synagogue the morning of the match.^[7]

Cohen defeated Jake Tuli on 14 December 1953, in Manchester, Lancashire, England, in ten rounds.^[4]

Before a crowd of 20,000, on 27 February 1954, Cohen took the European Bantamweight Title, defeating John Kelly in a third-round knockout in Belfast, County Down, Northern Ireland, Ulster. Cohen knocked Kelly to the mat for counts of four, seven and six in the second round. Kelly was down again at the end of the second from a right hook shortly before the bell. Thirty seconds into the third, Kelly went down for the full count from a right to the jaw.^[8]

World bantam champ

On 19 September 1954, he won the vacant World bantamweight title in a fifteen-round split decision in Bangkok, Thailand, against police Lieutenant Chamroem Songkitrat. An enormous crowd of 60,000 that included the King and Queen of Thailand watched the bloody contest. Cohen was left with a badly sprained or broken wrist in the fifth and his opponent with a broken nose. Cohen was formerly the European Bantamweight Champion.^{[9][10][11][3]} Later that year, his marriage took place at the Synagogue de la rue des Tournelles, in Paris, presided by Rabbi David Feuerwerker.

On 20 December 1954, he defeated Roy Ankrah in a fourth-round technical knockout in Paris.^[4]

Stripped of World bantam title

On 23 December 1954, Cohen was stripped of his title by the National Boxing Association for failing to defend it within 90 days against Raul "Raton" Macias. Few sanctioning bodies other than the NBA recognized Macias as the World Champion.^[12] Both the New York State Athletic Commission and the European Boxing Union continued to recognize Cohen as champion.^[13] On 11 December 1955 Cohen lost in a ten-round technical knockout against French featherweight champion Cherif Hamia before a crowd of 14,000. Cohen was down for an eight count in the second from a right cross to the jaw and was down again in the seventh from a right hook.^[14] The referee ended the bout 1:27 into the tenth round, when Cohen's left brow was injured by a left from Hamia.^[15][16] Some time after the bout, Cohen was severely injured in an automobile accident, and suffered a broken jaw. He attempted to defend his title, but the injury shortened his career.^[17]

On 3 September 1955, he drew with Willie Toweel in a fifteen-round world bantamweight title bout in Johannesburg, South Africa. Cohen dropped Toweel three times in the second and put him down for a no count in the tenth. Toweel had never been knocked to the mat in a previous bout.^[18] In a brutal bout, Cohen was deeply fatigued by the end of the match.^[19]

Cohen lost a title bout to Mario D'Agata on 29 June 1956 before a crowd of 38,000, in a seventh-round technical knockout in Rome. D'Agata dropped Cohen to the mat for a nine count near the end of the sixth. After the sixth ended, the referee stopped the fight due to a serious gash over the left brow of Cohen. D'Agata appeared superior in the in-fighting, and many of Cohen's blows were wide of his mark. America's National Boxing Association (NBA) did not recognize the match as a title bout, though nearly every other world boxing organization did.^[20] Only a year and a half earlier, D'Agata had been injured by a shotgun blast.^[21][22]

His professional record over 43 bouts was 36 wins (14 KOs), 4 losses, and 3 draws.