World No 1 Djokovic said he was pleased to have passed a huge test on his injured right ankle following a 4-6, 6-1, 6-4 defeat of Russian Mikhail Youzhny.
Djokovic admitted that at one point in the second set he felt some pain but played through it successfully, thanks in part to his heavy strappings.
Second seed Murray posted an uneventful 6-1, 6-4 win over Frenchman Eduardo Roger-Vasselin while Nadal began his favourite part of the year and a quest for a ninth straight title here with a 6-1, 6-2 defeat of Marinko Matosevic.
Djokovic had waited until the last minute to make his decision on whether he could compete, having rolled his ankle on Davis Cup duty 10 days ago.
He earned a late break for 5-4 in the final set as Youzhny missed a drop shot, before serving out the match. “I think that my ankle is in a good state as the days are passing by,” he said.