Novak Djokovic has insisted that his straight-sets victory over Ryan Harrison in the second round of Wimbledon was more difficult than the score suggests.
The defending champion saw off the 20-year-old American 6-4 6-4 6-4 in just under two hours on Centre Court on Wednesday night.
"It was a straight-sets win, but it was much more difficult than the scoreboard suggests," the Serbian world number one told BBC Sport.
"I was in trouble in the second set. It was difficult to adjust your movement under the roof; Ryan was serving fantastic and it made for a great match.
"It was a close match because he performed really well when he needed to but I got the crucial breaks when I needed to."
Djokovic will now face either Benjamin Becker or Radek Stepanek for a place in the last 16.