The world tennis number one Novak Djokovic was given a surprisingly tough test before reaching the quarter-finals of the Dubai Open.
Djokovic beat Sergei Stakhovsky, a hard-hitting Ukrainian 7-6 6-3, but he had to save a break point in the 8th game of the first set, and another early in the second set.
One more win could give Djokovic another semi-final against Andy Murray, a month after their classic five hour semi-final at the Australian Open.