Complex sentence: In 1974 Van Dillen had his best Grand Slam singles year reaching the last 16 in Paris where he narrowly lost to eventual champion Bjorn Borg in 5 sets, at Wimbledon he also reached the last 16 defeating Guillermo Vilas on the way.
Split into simpler sentences: 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. At Wimbledon he also reached the last 16, defeating Guillermo Vilas on the way.