Dowlen was the 1978 US National Junior Champion. He graduated from the University of Houston and was nominated twice for the All-American selection. At the university he met the Nigerian student and tennis player Nduka Odizor , who subsequently became his double partner. 1983 both won their first double title on the ATP World Tour in Monterrey . The following year was the most successful of their careers, they won two double titles and were in the finals of three other tournaments. In addition, Dowlen achieved his best individual result with the quarterfinals in Cleveland . In 1985 the fourth and last joint double title followed and another final participation. They were also in the quarterfinals of the Cincinnati Masters tournament .
In 1988 Dowlen won the double title of the Challenger tournament in Guadeloupe on the side of Marcel Freeman . In total, he won four ATP double titles in the course of his career, and was in a final four times. He reached his highest score in the tennis world rankings in 1984 with position 95 in singles and position 30 in doubles.
In singles, his best result in a Grand Slam tournament was participation in the second round at Wimbledon in 1982. In the doubles competition, he reached the quarter-finals of the US Open in 1983 . He was also in the round of 16 of the Australian Open and Wimbledon.
United States
Monterrey
Nduka Odizor
Tokyo
Sydney