1979 Australian Open (both played on grass). He was also the runner-up at the French Open three times (1975, 1978, and 1982) and at the Australian Open once (January 1977). In 1974, he won the year-end Masters Grand Prix title. In addition, he won seven Grand Prix Super Series titles (1975–80), the precursors to the current Masters 1000. Best year A left-handed baseliner, Vilas's best year on tour was 1977 when he won two of the four Grand Slam singles tournaments and 16 of the 31 Association of Tennis Professionals tournaments he entered. His playing record for 1977 was 130 wins against 15 losses. Not including the Masters year-end championship, he won 72 of his last 73 ATP matches in 1977. The highest point during this run was winning the last US Open played at Forest Hills against Jimmy Connors 2–6, 6–3, 7–6(7–4), 6–0 in a match where Vilas surprised his American rival by attacking the net. Winning streak In 1977 he won seven consecutive titles after Wimbledon—Kitzbühel (clay), Washington (clay), Louisville (clay), South Orange (clay), Columbus (clay), US Open (clay) and Paris (clay)—and set up a 46-match all-surface winning streak. He also had a record 53-match winning streak on clay courts, which stood until surpassed by Rafael Nadal in 2006. Both his winning streaks were terminated in October 1977 by Ilie Năstase in the final of the Raquette d'Or tournament. In that best of five-set final, Vilas dropped the first two sets by 6–1, 7–5 and then retired in protest of Năstase's use of a spaghetti strung racquet (which was banned shortly after by the ITF). After that he won a further 28 matches in a row with titles at Tehran, Bogotá, Santiago, Buenos Aires (all on clay), and Johannesburg (hard). That run was ended in the Masters semi-finals by Björn Borg. ATP ranking No. 1 controversy Even though he won 16 ATP singles titles, including the French Open and the US Open and was the runner-up at the January edition of the Australian Open in 1977, Vilas was never ranked by the ATP as world No. 1 during 1977 which was due to the fact that the rankings at the time were based on the average of a player's results. He was instead year-end world No. 2, behind Jimmy Connors (who won the Masters and seven other titles and was the runner-up at Wimbledon and the US Open