Cleveland's LeBron James, known for bouncing back stronger from playoff losses, promises such heroics Sunday in the NBA Finals after what he calls one of the toughest defeats of his career. Defending champion Golden State opened the best-of-seven championship series with a 124-114 over-time home victory Thursday after the Cavaliers led in the final seconds. Referees reversed a charging foul on Warriors forward Kevin Durant on video review into a blocking foul on James in the final minute of regulation time and Cleveland's J.R. Smith squandered a last shot chance in the fourth quarter apparently unaware the score was level.