Cink totaled 14 strokes in the extra session, while Watson needed 20 shots in the same stretch at Turnberry. The playoff was contested over Nos. 5, 6, 17 and 18 and was aggregate score
For Cink, this was his sixth PGA Tour win and first major championship. He had a chance at getting into a playoff at the 2001 U.S. Open, but missed a short putt on the 72nd hole that cost him that spot.
Watson had been going for his record-tying sixth Open Championship title and was trying to become the oldest major champion.
Cink posted a one-under 69 in regulation, that included a birdie on the 72nd hole to post two-under-par 278.
Watson, led by one on the 18th tee, but knocked his approach over the green at the last and could not save par. Watson shot two-over 72 in the final round to match Cink at minus-two.