Tennis world number ones are usually grand slam champions, Roger Federer, Serina Williams, and Andy Murray are a few examples. But it's possible for a player to become the top seed collecting points by making deep runs in the grand slams and winning non major titles.
Has there been a time when a man or a woman reached singles first seed before ever winning a major? If so please list them all, also did they to win a grand slam afterwards?
Ivan Lendl was the only player in the list who has won singles
grand slams prior to Wozniacki winning her only slam in 2018. He's known as one of the greatest players ever, holding
the world #1 for 270 weeks (the 3rd most all time by a male player).
He reached #1 seed first time in 1983. In 1984 he won his first grand
slam at the French Open after four major finals losses. Lendl has won
8 majors championships, having won all grand slams except for
Marcelo Rios was the top seed for only 6 weeks in 1998. In his
only grand slam finals appearance he lost to Petr Korda in the 1998
Caroline Wozniacki finished 2010 and 2011 as the top seed, in
total she's been the world #1 for 67 weeks. Despite winning 25 WTA
titles, she's never won a grand slam. Her only grand slam finals
happened in the US open in 2009 and 2014. EDIT: Before retiring, Wozniacki won the 2018 Australian Open. The championship propelled her to the #1 ranking once more, but this time as a grand slam champion.
Jelena Jankovic reached the top seed in 2008 and finished the
year in that spot, making her the first player in WTA to finish a
year as world #1 without wining a grand slam. Her only singles majors
finals was the 2008 US open. It is noteworthy that she won a grand
slam in mixed doubles of 2007 Wimbledon with Jamie Murray.
Dinara Safina became world #1 in 2009. She made the most singles
grand slam finals without a championship among the players in this
list. She was the runner up in 2008 and 2009 French Open as well as
the 2009 Australian Open. Similar to Jankovic, Safina's only majors
championship came in the doubles. She won the 2007 US open women's doubles
with Nathalie Dechy.