5 dark horses in this year's US open

Dark horse no. 2: Marin Cilic

Croatia's Marin Cilic Dark horses The towering Croatian is coming into US open with a brilliant win against world no. 2 and Wimbledon and Olympic champion Andy Murray at Cincinnati open. Cilic is the 2014 US open champion and is currently ranked no. 6, so he knows how to play on the big stage. He has got a booming serve, something that makes him a really tough opponent to play. He also reached the quarter finals of Wimbledon this year and held three match points against Roger Federer before squandering his chances. Cilic recently parted ways with long-time coach Goran Ivanisevic and hired Jonas Bjorkman to help straighten his forehand and returns. After his win at Cincinnati, Cilic, one of the dark horses, is oozing onfidence and is looking to add to his tally of titles after winning US open in 2014.