No, so far. He had beaten Nuah Kahn to become a Muay Thai Emperor and defended the title against many fighters (the only known challenger is Go Hibiki, Dan's father).
He organized the first Street Fighter tournament and Ryu won it (we all know how).
The second tourney was interrupted by Akuma killing Bison (Ryu versus Bison was supposed to be the final match). However, Ryu defended the title as he was winner by default or so. Sagat retired from that tournament as he was searching for inner focus or so.
The next tournament is organized by Seth's SIN organization (SF4) and it is currently unknown who've won it. It is possible that Sagat went far on the tourney and even reached the final against possibly Ryu (he surely had his rematch with Ryu during SF4, it's just unsure if it was a final match, a random encounter and who won). Hopefully Capcom reveals some details about it.
The last tournament was SF3 2nd Impact organized by Gill. Alex won it, Sagat didn't participate.
So, here's the list Sagat's known battles so far:
Nuah Kahn - Sagat won it. Bunch of unknown challengers - Sagat beats them all.
Go Hibiki - Sagat won. He lost his eye and beat Hibiki to death.
(SF1) Ryu - Ryu wins. Sagat beats down Ryu and thinks that he won, goes to help Ryu to get up, but Ryu's evil intent does the job.
(SFA2) Adon - Adon wins but gets seriously wounded. Sagat wasn't focused to fight due to his previous loss to Ryu.
(SFA2) Dan - Dan wins to avenge his father's death (Sagat actually let him win though).
(SFA3) Ryu - Sagat beats Ryu but finds out that he was brainwashed by Bison. That somehow helped Ryu who then got back to normal.
(SF4) Adon - Sagat wins easily with "Tiger Destruction" move.
(SF4) Ryu - true rematch. It's unknown who won, but could've gone either way (note that during SF4 Ryu and Sagat are around the same level). At Sagat's ending he's happily going back to Thailand and reveals that he had "met" Ryu.