Defending Masters champion Rory McIlroy experienced a dramatic third-round collapse at Augusta National, surrendering what had been a commanding six-shot lead heading into Sunday's final round.

McIlroy, who entered Saturday in control of the tournament, struggled during the third round and now faces a challenging final day as he attempts to successfully defend his green jacket.

The Northern Irishman acknowledged after his round that he will need to significantly improve his play on Sunday if he hopes to retain his Masters title. His third-round stumble has completely altered the tournament dynamics.

McIlroy's difficulties have opened the door for a competitive field of contenders who now find themselves in position to challenge for the championship. The final round is expected to feature multiple players with realistic chances of claiming the green jacket.

The tournament, which appeared headed for a potential runaway victory through two rounds, now promises a dramatic conclusion as the field tightens considerably. Sunday's final round will determine whether McIlroy can recover from his Saturday struggles or if a new champion will emerge at Augusta National.