Borwick became a professional tennis player in 1987. As a lucky loser , he survived the first round of the Bristol Grand Prix tournament in 1988. As a result, he played mainly on the ATP Challenger Tour and was able to win his first individual title there in August 1989 in Kuala Lumpur . In the same year he reached two more individual finals on the Challenger Tour, in which, however, he lost his finals. It was not until 1994 that he was able to win his second and last individual title. He was more successful as a doubles player. In the course of his career he was able to win six tournaments on the Challenger Tour and one tournament victory on the ATP World Tour . He reached his highest ranking in the tennis world rankings in 1993 with position 104 in singles and 1992 with position 60 in doubles.
His best individual result at a Grand Slam tournament was reaching the second round of the Australian Open in 1990 and 1993, as well as the second round of the US Open in 1993 by defeating Ivan Lendl . In the doubles competition he reached the second round of Wimbledon and the quarter-finals of the Australian Open and the US Open in 1992 on the side of Simon Youl . His best result in mixed was a second round participation at Wimbledon in 1989.