Leonard overcame a one-shot deficit in the final round on Sunday to overtake Davis Love III for his eighth career victory on the PGA Tour.
Tiger Woods, who will be looking for his fourth straight Bay Hill Invitational title, will take his No. 1 ranking into the weeks to come as he prepares for The Masters. Ernie Els remained firmly entrenched as the second-ranked golfer in the world.
Phil Mickelson kept his position in third followed by Vijay Singh. David Toms exchanged places with Retief Goosen this week to come in at No. 5 with the South African falling to sixth.
Love held on to the seventh spot while Sergio Garcia, Mike Weir and Padraig Harrington stayed put to round out the top 10.
Jim Furyk and Scott Hoch kept their spots at 11 and 12, respectively. Chris DiMarco jumped one position to 13th while Nick Price dropped one to No. 14.
Leonard was 15th followed by Rocco Mediate, who fell one rung to 16th. Charles Howell III lost one spot to drop to 17th as did Colin Montgomerie, who fell to No. 18. Jerry Kelly and Robert Allenby completed the top 20.
Darren Fichardt defeated James Kingston in a playoff to capture the Qatar Masters on Sunday. Fichardt, who won for the first time since his breakthrough victory at the 2001 Sao Paulo Brazilian Open, vaulted 78 places to come in at No. 145 this week. Kingston, still in search of his maiden title on the European Tour, cracked the top 200 at No. 172.