Andy Murray has dropped to eighth in the ATP world rankings - his lowest position in almost six years.
The Wimbledon champion, who recently split with coach Ivan Lendl, falls below Tomas Berdych and Juan Martin Del Potro in the current standings after failing to defend his ranking points at the Sony Open.
Murray had won the Masters title in Miami 12 months ago, however his quarter-final defeat to eventual champion Novak Djokovic has cost him heading into the clay court season.
The British No 1 is now in danger of falling out of the top eight before the French Open and Wimbledon given that clay is his least favourite surface.
Djokovic remains second to Nadal in the latest rankings, although his win in Miami, which came hot on the heels of success in Indian Wells, has seen him cut the gap to the Spaniard to fewer than 2,000 points.
Roger Federer returns to the top four for the first time since Wimbledon last year, replacing David Ferrer, who falls to sixth.
Australian Open champion Stanislas Wawrinka remains third with Berdych now fifth and Del Potro seventh.
Then comes Murray in eighth. The last time he was ranked that low he was just 21 and had yet to play in a Grand Slam final.
John Isner and Milos Raonic make up the top 10, returning to their career-high rankings of ninth and 10th respectively.
In the women's rankings, Serena Williams remains number one by some distance after successfully defending her title in Miami - she has now won the event seven times in her career.
Beaten finalist Li Na is second ahead of Agnieszka Radwanska and Victoria Azarenka. Maria Sharapova slips to ninth.
British number one Laura Robson is down to 57th - she continues to be absent from the tour due to a wrist injury.