Scott looked set to win his first major title at Royal Lytham when he birdied the 14th hole of his final round to stand 10 under par, but the 32-year-old Australian then bogeyed the next three holes.
Els, second and third when the Open was staged at Lytham in 1996 and 2001 respectively, had finished in style with a birdie on the 18th to complete a closing 68 and set the clubhouse target on seven under par. Scott found a fairway bunker off the 18th tee but still had the chance to force a four-hole play-off after hitting his third shot to eight feet, but missed as Els looked on from the putting green.
Americans Tiger Woods (73) Brandt Snedeker (74) shared third place on three under 277. It was Els’ fourth major title after his wins at the 1994 and 1997 US Opens and at the 2002 British Open.