Pat thighs dry. Heat oil in wide heavy pot over medium; brown skin-side down 7 to 8 minutes. Turn; cook 3 minutes. Spoon off excess fat, leaving about 1 tablespoon.
Add garlic around thighs; cook 1 minute. Add soy sauce, vinegar, water, bay, pepper, and sugar.
Gently simmer; cover and cook over low 30 to 35 minutes, turning once, until thickest meat 175 to 185°F and tender when pierced.
Platter chicken. Simmer sauce uncovered 5 to 10 minutes until slightly reduced but pourable; remove bay.
Return chicken 1 minute; turn to coat. Serve with softened garlic and small spoonful sauce per thigh.