MADRID — Victoria Azarenka lost her temper, broke her racket and argued with the chair umpire in an inglorious exit Wednesday from the Madrid Open, where she's been runner-up the last two years. Losing to Ekaterina Makarova of Russia 1-6, 6-2, 6-3 in the second round ended Azarenka's 18-match winning streak to start the season. Meanwhile, Rafael Nadal spoiled Benoit Paire's 24th birthday by sweeping past the Frenchman 6-3, 6-4. Azarenka berated umpire Mariana Alves after picking up a second code violation for smashing her racket in the third set. “After all you've done, how are you still in the game?” the third-seeded Azarenka shouted at the official while on court. Azarenka said she felt confused by some refereeing decisions. “I didn't understand what happened, what I did,” she said. “I was very sure that I didn't have a code violation, that's why I broke my racket.” The fifth-ranked Nadal's hopes of returning to the top four in time for the French Open were boosted by Novak Djokovic's surprise loss to Grigor Dimitrov of Bulgaria 7-6 (6), 6-7 (8), 6-3 Tuesday. Sixth-seeded Tomas Berdych of the Czech Republic beat Jerzy Janowicz of Poland 6-7 (3) 6-3, 6-2 and Kei Nishikori of Japan downed Viktor Troicki of Serbia 7-5, 6-2. Djokovic — who ended Rafael Nadal's eight-year winning streak at the Monte Carlo Masters last month — said the loss had more to do with poor preparations than an injury. Tomic's father barred from all ATP events The father of Australian tennis player Bernard Tomic was barred Tuesday from being accredited to upcoming ATP events pending an investigation into allegations that he assaulted his son's training partner ahead of this week's Madrid Open. John Tomic was charged with assault after allegedly head-butting the hitting partner, Thomas Drouet, on Saturday outside the player hotel in Madrid. A Madrid court said Monday that John Tomic disputed the charges and will face trial May 14. Singapore grabs WTA Championships in record deal Singapore Wednesday won the right to host the showpiece WTA Championships from 2014 in a record five-year deal which looks set to give a huge boost to tennis in Asia. The wealthy Southeast Asian city-state beat rival bids from China's Tianjin and Monterrey in Mexico for the season finale, which next year will boast a purse of $6.5 million, its largest ever. The arrival of the tournament, the biggest in the Asia-Pacific region after the Australian Open Grand Slam, comes with Asian tennis still expanding on the back of Li Na's historic French Open win in 2011. — Agencies