After winning the NCAA Singles championships in 1976 as a sophomore for Trinity University (upsetting UCLA's Peter Fleming), Scanlon turned pro and, in his first Grand Prix event, defeated world #7 Harold Solomon to reach the quarter-finals. His first ever ATP singles ranking was No. 154. Later that summer, Scanlon defeated world no. 4 Adriano Panatta at the US Open and, with two wins over former world #1 Ilie Năstase in early 1977, climbed the rankings to No. 23 by March 1977.