Maria Sharapova, a five-time Grand Slam winner, retires at age 32

Powerful at the baseline, and famous for a never-give-up attitude, Sharapova reached No. 1 for the first time at 18 in 2005. After adding her second major trophy at the U.S. Open the following year, she collected an Australian Open title in 2008, and then won the French Open in 2012 and 2014.