McIlroy and English both won six of their first 18 holes and split the other six before English won the first playoff hole with a par while McIlroy double bogeyed.
McIlroy was down two with five to play before birdieing three straight to put English down one with two left. English birdied No. 17 before they both parred No. 18 and went to the 19th hole.
English told Golf Channel the day was a roller coaster but he just tried to hang in to the end.
"Rory's an unbelievable player. I knew he hadn't been hitting it his best in the middle holes. I knew I had to birdie 17 or 18 to get back in it.
"I knew what I was getting into today. I knew it was going to be a tough match. Had to take it into the end."
Since making it to the finals of this tournament two years ago, McIlroy has now bowed out in the first and second rounds in consecutive years.