​Novak Djokovic defeated Nuno Borges, 6-3, 7-6, in the first round of the China Open.In doing so, Djokovic extended his unbeaten run in Beijing. The Serb has now won 30 consecutive matches at the China Open since debuting at the event back in 2009.During his 30-match winning streak, Djokovic has dropped sets to just two players. What better time than now to look back at those slight blemishes on his record?Novak Djokovic dropped sets to Fernando Verdasco and Michael Berrer at the China OpenDjokovic has only lost three sets at the China Open, but lost his first after just three matches in Beijing. After defeating Victor Hanescu and Viktor Troicki, Djokovic met Fernando Verdasco in the 2009 China Open quarter-finals.He won the opening set 6-3 and looked on course for the semi-finals before Verdasco, then a top-10 player, took control in the second set. The Spaniard began to dominate Djokovic and won the set 6-1 to force a decider. Unfortunately for Verdasco, his level dropped in the third, and he fell to a 3-6, 6-1, 1-6 defeat.Djokovic won seven straight-set matches and two titles before encountering any more trouble at the China Open. He dropped his next set in the first round of the 2012 China Open, against Germany’s Michael Berrer.The world number 123 had advanced through the qualifying tournament to reach the main draw and was determined to make the most of his opportunity. After losing the first set 6-1, Berrer pushed Djokovic all the way to a tiebreaker in the second. Playing some of his best tennis in the crucial moments, the German won the tiebreaker 7-6 (7-3). He then suffered the same fate as Verdasco in the third set and ran out of steam. Djokovic survived, beating Berrer, 6-1, 6-7, 6-2.Djokovic didn’t lose a set for the remainder of the tournament as he won his third China Open title. He then won his opening match in 2013 before facing Verdasco again in a rematch of their 2009 clash.Verdasco, ranked 22 places lower than he was in 2009 (31), walked onto the court as a major underdog against the world number one, but was determined to deliver an upset. After a tight first set went against him, losing 5-7, Verdasco won the second, 6-2, to move within touching distance of the win. He couldn’t finish the job, though, and lost the final set 6-2.Djokovic hasn’t lost a set in Beijing since. The Serb is a record six-time champion and remains unbeaten at the China Open.Novak Djokovic’s 30 wins at the China OpenYearPerformanceMatch wins2009Champion5 (Victor Hanescu, Viktor Troicki, Fernando Verdasco, Robin Soderling, Marin Cilic)2010Champion4 (Gong Maoxin, Gilles Simon, John Isner, David Ferrer)2012Champion5 (Michael Berrer, Carlos Berlocq, Jurgen Melzer, Florian Mayer, Jo-Wilfried Tsonga)2013Champion5 (Lukas Rosol, Fernando Verdasco, Sam Querrey, Richard Gasquet, Rafael Nadal)2014Champion5 (Guillermo Garcia-Lopez, Vasek Pospisil, Grigor Dimitrov, Andy Murray, Tomas Berdych)2015Champion5 (Simone Bolelli, Zhang Ze, John Isner, David Ferrer