Complex sentence: Wawrinka went on to win the title by defeating Rafael Nadal in the final, 6--3,6--2,3--6,6--3, ending the run of the Big Four, stretching back to the 2009 US Open.
Split into simpler sentences: Wawrinka went on to win the title by defeating Rafael Nadal in the final, 6--3,6--2,3--6,6--3. He ended the run of the Big Four, stretching back to the 2009 US Open.