In 1937, the New York State Athletic Commission named Frank Apolstoli and Solly Krieger number one, and number two respectively in their divisions. To determine which boxer would reign as the number one middleweight, Krieger and Apostoli fought on April 4, 1937, at the Hippodrome in New York. Suffering from a deep cut in his lower lip, Krieger had to discontinue the fight, resulting in a TKO in the fifth round. Doctor William Walker made the determination to end the bout at the end of the fifth but had considered ending the fight in the prior round. Krieger had previously lost to Apostoli on February 17, 1937 on points in an exciting ten round bout at the Hippodrome. Both bouts were a setback for Krieger, but not an end to his quest for the title.