Briton Kyle Edmund rose three places to 23 in the ATP world rankings released on Monday following a run to the final in Marrakech last week.
The only move in the top 20 saw Spain's Roberto Bautista swap 16th and 17th places with American Jack Sock.
Rafael Nadal retains the world number one spot but has a lot of points to defend before the French Open starts next month, starting with this week in Monte Carlo.
Last year, he won titles in Monte Carlo, Barcelona and Madrid and a failure to record a clean sweep again this year could give number two Roger Federer the chance to reclaim top spot.
ATP rankings as of April 16:
1. Rafael Nadal (ESP) 8,770 points
2. Roger Federer (SUI) 8,670
3. Marin Cilic (CRO) 4,985
4. Alexander Zverev (GER) 4,925
5. Grigor Dimitrov (BUL) 4,635
6. Juan Martín Del Potro (ARG) 4,470
7. Dominic Thiem (AUT) 3,665
8. Kevin Anderson (RSA) 3,390
9. John Isner (USA) 3,125
10. David Goffin (BEL) 3,110
11. Lucas Pouille (FRA) 2,410
12. Pablo Carreño (ESP) 2,395
13. Novak Djokovic (SRB) 2,310
14. Sam Querrey (USA) 2,220
15. Diego Schwartzman (ARG) 2,220
16. Roberto Bautista (ESP) 2,175 (+1)
17. Jack Sock (USA) 2,155 (-1)
18. Tomás Berdych (CZE) 2,140
19. Hyeon Chung (KOR) 1,897
20. Fabio Fognini (ITA) 1,840
Selected others:
23. Kyle Edmond (GBR) 1,757 (+3)