Kaymer, the 2010 PGA Championship winner, finished the tournament on 20-under-par 268, three shots clear of runner-up Fredrik Jacobson of Sweden.
Northern Ireland's Graeme McDowell was third a shot further back, with his countryman Rory McIlroy one of three players to finish in joint fourth place, along with England's Paul Casey and South African Charl Schwartzel.
The star of the day was undoubtedly Kaymer, who produced a stunning run of nine birdies in his final 12 holes to turn a five-shot deficit to overnight leader Jacobson at the start of the day into a three-shot win.
After playing the first six holes to par, Kaymer started his charge with a birdie on the 346-yard par four seventh, before adding another on the eighth.
It was the inward nine where the 26-year-old really shone though, as he recorded four successive birdies from the 10th to 13th, and then three more on the 15th, 17th and 18th as he came back in just 29 shots.