Complex sentence: He was the second person to earn a "battlefield promotion" to the PGA Tour by winning three Nationwide Tour events in the same season, and only the second player in Nationwide Tour history to complete 72 holes without a bogey.
Split into simpler sentences: He was the second person to earn a promotion to the PGA Tour by winning three Nationwide Tour events in the same season (this is commonly referred to as a "battlefield promotion"). He is only the second player in Nationwide Tour history to complete 72 holes without a bogey.