Brown chicken in oil over medium-high heat, 8-10 minutes. In batches if the pieces don't fit comfortably.
Place thighs in crock pot. Cover and cook on LOW for 6-7 hours.
About 30 minutes before serving, in 1-quart saucepan, heat sauce ingredients over medium heat 10 to 15 minutes, stirring occasionally, until thickened.
Drain excess liquid from crock and pour sauce over chicken. Cook 10-15 minutes longer.