Andy Murray lost the Madrid Open men's singles to Novak Djokovic to be overtaken by Swiss ace Roger Federer.
Pete Sampras won his last major at the 2002 US Open and Andre Agassi's final Slam trophy was hoisted at the 2003 Australian Open. Then came Andy Roddick at the 2003 US Open, a win that helped him to world number one until February of 2004.
Serb has won only once at Flushing Meadows and wants more.
Ranked 12th in the world, American John Isner has won two of his nine career titles in Atlanta, where he also lost to Mardy Fish in the 2010 and 2011 finals and to eventual champion Andy Roddick in the 2012 semi-finals.
Navratilova said she expects the American to equal her total of 18 Grand Slam singles titles at the Australian Open starting in Melbourne this month and go on to better Graf's record of 22.
In what could be a dress rehearsal for the Australian Open final, Williams won a close first set then edged Azarenka in the second to win 6-4, 7-5 in 98 minutes.
Nadal's 4-6, 6-2, 6-3 victory over
It was only the second time in 10 attempts that Ivanovic has beaten the 33-year-old Williams, who has not won a title since October 2012.
The Spaniard has never previously won an ATP World Tour title in the first week of the season, but he is on course to do so this time after seeing off Gulbis, the only other seeded player left in the draw.
India will host the first Wimbledon tennis event outside the UK as 11-time-Tour winner Tim Henman will be in Delhi and Mumbai later this month to launch 'The Road to Wimbledon' with a series of coaching clinics.
Murray lost 3-6, 6-4, 6-2 to Florian Mayer, the world number 40 from Germany, who seemed more surprised than anyone at how the contest turned around.
The Spaniard believes that treatment on his troublesome knees may prolong his career, but admits that the delay in restarting work during the off season has reduced his chances of regaining the Australian Open title in two weeks time.
The 32-year-old won only one title in an injury-hit 2013, leading many tennis fans to wonder whether he would add to his record tally of 17 Slams.
The former world number one hurt her shoulder during training and decided to pull out of Brisbane to avoid the risk of further damage.
Wawrinka emerged from the shadows of legendary compatriot Roger Federer with a string of major semi-final appearances that lifted him into the top 10 after starting 2013 ranked 17th.
Federer said he had had a rare off-season free of niggling injuries and was looking forward to challenging the world's best.
Roger Federer, owner of a record 17 Grand Slam titles, says on Friday on Facebook that six-time major champion Edberg "agreed to work with us for at least 10 weeks starting at the Australian Open."
It was the world number one's first match since losing in straight sets to Novak Djokovic in the final of the World Tour Finals in London on November 11.