Austrian tennis player Dominic Thiem on Wednesday upset defending champion Novak Djokovic of Serbia at the French Open, advancing to the semi-finals where he will face Rafael Nadal.Seeded sixth in the tournament, the 23-year-old Thiem won 7-6(5), 6-3, 6-0 over Djokovic in two hours and 15 minutes, reports Efe."All in all, it was decided I think in the first set. I tried. I lost that crucial break in the beginning of the second (set), and he started serving better, backing it up with the first shot," Djokovic said."He deserved to win. He was definitely the better player on the court today," he added.The Serbian, who became the eighth player in tennis history to complete the Grand Slam at Roland Garros last year, is set to lose his second place in the ATP rankings for the first time in seven years, in favour of third-placed Swiss Stan Wawrinka or fourth-placed Nadal.
Earlier, Nadal defeated fellow Spaniard Pablo Carreño Busta, who withdrew with abdominal pain after 51 minutes of play. Bidding for his 10th French Open title, Nadal won 6-2, 2-0 after Busta withdrew.Busta, a first-time Grand Slam quarter-finalist, complained of pain in his lower abdomen and requested assistance from the physician during the first set.The 25-year-old Spaniard finished the set by committing two consecutive double faults and after being taken care of on the court, left for a few minutes.On his return, his service was weakened, as it had been throughout the game and eventually he decided to retire after losing 0-2 in the second set. That helped Nadal to become the first player to enter the French Open semi-finals for the 10th time.