In 1974, van Dillen had his best Grand Slam singles year reaching the last 16 at the French Open where he narrowly lost to eventual champion Björn Borg in five sets.

Van Dillen's last full year on the circuit was 1981 when he won two doubles titles and reached the semifinals of the Volvo International in North Conway with Roscoe Tanner.

[citation needed] Between 1960 and 1981, he beat six of the then-top players: John McEnroe,[2] Stan Smith,[3] Arthur Ashe,[4] Jimmy Connors,[5] Guillermo Vilas,[6] and Ilie Năstase.

While at IMG, Erik worked with Joe Montana, Martina Navratilova, Arnold Palmer, Kristi Yamaguchi and Chris Evert and helped to build a number of sport and lifestyle events including the WTA Bank of the West Tennis Classic (formerly the Virginia Slims of Oakland), the US Open of Surfing (a 10-day sports and lifestyle exhibition), the Transamerica Seniors Golf Championship and the Escape from Alcatraz Triathlon.

[citation needed] After the death of Mark McCormack in 2003, Erik left the company to create van Dillen Partners, a sports and lifestyle marketing agency.