answers: Marin Čilić
context: defeat the World No. 1 at a Grand Slam by defeating Rafael Nadal in the fourth round since 1992, when Andrei Olhovskiy defeated then World No. 1 Jim Courier in the third round of the 1992 Wimbledon Championships. The final was the first Grand Slam men's singles final since the 2009 US Open to feature neither Murray nor Nadal. Although Nadal was World No. 1 entering the tournament the Spaniard was seeded second behind Novak Djokovic due to his recent poor performances on grass (as well as his early exits at Wimbledon the previous two years). After claiming the title </s> 2014 Australian Open – Men's Singles Novak Djokovic was the three-time defending champion, but lost in the quarterfinals to eventual champion Stanislas Wawrinka, bringing Djokovic's 25-match winning streak at the Australian Open, 28-match winning streak overall, and streak of 14 consecutive Grand Slam semifinals to an end. Rafael Nadal was trying to become the third man to complete a double career Grand Slam and was also trying to tie Pete Sampras's record of 14 Grand Slam wins. Eighth seed Wawrinka won the title by defeating top seed Nadal in the final, becoming the first man outside the Big Four to </s> Andy Murray was beaten before the quarter-finals of a Grand Slam tournament, losing to Kevin Anderson in the fourth round. This ended a streak of 18 consecutive Grand Slam quarter-finals (he missed the 2013 French Open due to injury). This was also the last Grand Slam tournament for former World No. 7 Mardy Fish and former top fifteen player Jarkko Nieminen. 2015 US Open – Men's Singles Marin Čilić was the defending champion, but was defeated by the eventual champion, Novak Djokovic in the semifinals. Djokovic went on to win the title, defeating Roger Federer in the final, 6–4, 5–7,
question: who won the men 's singles title of the us open tennis grand slam 2014