Today's contest featured a host of wonderful rallies with both men pushed to the limit.
"It was a great match, great fun," said Djokovic. "He is a very talented player.
"He made a lot of great first volleys and made me play the extra ball. He was chipping and charging, not a lot of players do this any more."
Djokovic will play either Sam Querrey or Stanislas Wawrinka in round four.