Detailed Instructions: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Problem:An emotional Jason Day finally seized victory in a major at the US PGA Championship on Sunday and insisted 'no one was going to stop me' after a number of near misses in previous events. Day lifted the Wanamaker Trophy after becoming the first player to win a major with a score of 20-under par on the Whistling Straits course. He was three shots clear of Jordan Spieth in second. And after six top-10 finishes in majors since coming third in the Masters at Augusta in 2013, questions have been posed as to whether Day had the nerve to ever land one of the big four tournaments. Now, the 27-year-old Australian has answered his critics emphatically.Jason Day beat Jordan Speith by three shots to win US PGA ChampionshipThe 27-year-old cried on the 18th green as his first major was sealedAfter plenty of near misses, Day was determined not to surrender his lead 
 Question:Playing with _ was very difficult, just watching what he was doing and on top of it, grinding it out as hard as I possibly could.
Solution:
Jordan Spieth