Quick stopped 25 shots in the Kings' home opener, but the star goalie also misplayed McDonagh's harmless cleared puck from deep in the New York end early in the third period, knocking it into his own net.
Henrik Lundqvist made 28 saves, and Rick Nash assisted on both of Richards' goals for the Rangers, who are opening the season on a nine-game road trip.
Jake Muzzin scored for the Kings, who have scored just six goals in three games this season.
Once again, it shows character in this dressing room. Once again, there's no quitting in here. We all wanted this so bad and we worked so hard to get home-ice advantage and we weren't going to let this one slide.
— Colorado Avalanche captain Gabriel Landeskog on his team's OT Game 1 win vs. Minnesota Wild