Despite not playing since the Australian Open, Rafael Nadal has reclaimed top spot in the ATP rankings after Roger Federer crashed out early in Miami.
Nadal, who hasn't hit a ball in anger since pulling out of the Aus Open quarter-finals in January, saw Federer take over top spot on February 18.
However the Swiss veteran has now slipped 10 points behind his Spanish rival and into second place after a second round defeat to Thanasi Kokkinakis.
Federer's 2017 titles at Indian Wells and Miami meant he had a mile of rankings points to defend, and his inability to defend his titles saw him slip in the rankings.
"I deserve it after this match," Federer said. "That's how I feel."
Kokkinakis became the lowest-ranked man to beat a No. 1 player since No. 178 Francisco Clavet upset Lleyton Hewitt in 2003.
It's the first time since 2014 that Federer has lost back-to-back matches, a surprising dip considering his career-best 17-0 start to the year.
Towering American John Isner leapt eight places to ninth thanks to his eventual victory in the Masters 1000 event.
Isner thus equals his previous best ranking of ninth, reached in April 2012, while beaten finalist Alexander Zverev of Germany moved up one place to fourth.
South Korea's Hyeon Chung meanwhile continued to chip away at the rankings, the 21-year-old breaking into the top 20, to 19th, for the first time in his fledgling career thanks to his quarter-final appearance in Miami.
ATP rankings at April 4 (change in ranking in brackets):
- Rafael Nadal (ESP) 8770 pts (+1)
- Roger Federer (SUI) 8670 (-1)
- Marin Cilic (CRO) 4985
- Alexander Zverev (GER) 4925 (+1)
- Grigor Dimitrov (BUL) 4635 (-1)
- Juan Martin Del Potro (ARG) 4470
- Dominic Thiem (AUT) 3665
- Kevin Anderson (RSA) 3390
- John Isner (USA) 3125 (+8)
- David Goffin (BEL) 3110 (-1)
- Lucas Pouille (FRA) 2410 (-1)
- Pablo Carreno (ESP) 2395 (+7)
- Novak Djokovic (SRB) 2310 (-1)
- Sam Querrey (USA) 2265
- Diego Schwartzman (ARG) 2220 (+1)
- Jack Sock (USA) 2200 (-5)
- Roberto Bautista (ESP) 2175 (-2)
- Tomas Berdych (CZE) 2140 (-5)
- Hyeon Chung (KOR) 1897 (+4)
- Fabio Fognini (ITA) 1840 (-2)