Martina Hingis won less than 5 Grand Slam mixed doubles titles .
1 and has won five Grand Slam singles titles ( three at the Australian Open , one at Wimbledon , and one at the US Open ) , twelve Grand Slam women 's doubles titles , winning a calendar-year doubles Grand Slam in 1998 , and four Grand Slam mixed doubles titles ; for a combined total of twenty-one major titles .
Martina Hingis