The four Grand Slam championships represent the pinnacle of achievement in the sport of tennis. In 2002, Pete Sampras won his 14th Slam at the U.S. Open, extending his own record for the most Grand Slam singles titles won by any male player. Federer bested this mark in 2009, winning the Wimbledon championship that year to take his 15th Grand Slam title. He then went on to win five more Slams, becoming the first man to reach 20 Grand Slam victories at the 2018 Australian Open. Not only did Federer surpass Sampras's overall record, but in fact he won as many or more titles than Sampras at each of the four Slam tournaments individually. Federer's breakthrough successes ushered in what has been referred to as a golden age for men's tennis, with Federer dominating virtually every Grand Slam alongside his chief rivals, Rafael Nadal and Novak Djokovic, for the better part of two decades.