Complex sentence: This was del Potro's first and only major title and also was the only major not won by one of the Big Four between the 2005 Australian Open and the 2014 Australian Open, a span of 35 events.
Split into simpler sentences: This was del Potro's first and only major title. It also was the only major not won by the Big Four between the 2005 Australian Open and the 2014 Australian Open, a span of 35 events.