Muay Thai

Normally fighting with elbows, kicks to the shin and knees to the soft bits is considered pretty poor form but it's all allowed in Muay Thai boxing. As well as fighting with all eight points of contact or pointy bits (headbutting is no longer allowed), Muay Thai involves some grappling and some clinching, which looks like hugging, and because the legs and elbows are so involved it's a lot more physically interesting to watch than a western boxing match. A normal night at the fight will have about 10 matches scheduled, though some will be over pretty quickly, with traditional music and entertainment between the bouts.
The national sport, Thai boxing can be seen at Rajadamnern and Lumpinee Stadiums. The bad news is that visitors are expected to show their enthusiasm via considerably inflated ticket prices—which can be on the more expensive floor, or the more rowdy second tier. Visitors should also heed advice to keep their hands still—a complicated betting system of hand signals goes on and you don't want to accidentally place a few bets as you cheer. Fight nights are Mondays, Wednesdays, Thursdays and Sundays.