McIlroy four off lead heading into final round of BMW Championship

Four-time major winner Rory McIlroy is four shots off the lead heading into the final round of golf's BMW Championship in Maryland.

The Northern Irishman is part of a quartet of players in a tie for fourth.

Bryson DeChambeau let his four-shot lead slip and begins the last day tied with fellow American Patrick Cantlay on 21 under.