Ken Flach, who won four Grand Slam titles in men’s doubles and two in mixed doubles, died on Monday in California. He was 54.
The ATP World Tour, which represents men’s professional tennis, announced his death. His wife, Christina, said on Facebook that he had had pneumonia.
Flach and Robert Seguso formed one of the top teams of the 1980s, reaching No. 1 in the men’s doubles rankings in 1985. They won 28 titles together, including championships at the United States Open in 1985 and at Wimbledon in 1987 and 1988. They were the runners-up at the Open twice.