INDIAN WELLS, CA - MARCH 11:  Grigor Dimitrov of Bulgara challenges a call during his match with Ernests Gulbis of Latvia during the BNP Paribas Open at Indian Wells Tennis Garden on March 9, 2014 in Indian Wells, California.  Gulbis won 2-6, 6-1, 7-5.  (Photo by Stephen Dunn/Getty Images).  (Photo by Stephen Dunn/Getty Images)