Complex sentence: In May 2014, Kaymer won the The Players Championship--the flagship event of the PGA Tour--a month later, he led each round of the U.S. Open and won his second major by eight strokes.
Split into simpler sentences: In May 2014, Kaymer won the The Players Championship, the flagship event of the PGA Tour. A month later, he led each round of the U.S. Open and won his second major by eight strokes.