Novak Djokovic sees off Ryan Harrison

Defending champion Novak Djokovic has reached the third round of Wimbledon after a straight-sets victory over American Ryan Harrison on Centre Court.

The world number one broke midway through the first set on his way to a 6-4 triumph.

Harrison, who was making only his second appearance at the Championships, looked comfortable on the big stage and pushed his opponent hard throughout.

However, Djokovic tightened his grip on the contest as he broke in the second to take it again 6-4.

With both players refusing to budge at the start of the third, Djokovic finally made the breakthrough before another 6-4 win.

The Serbian will now take on either Benjamin Becker or Radek Stepanek for a place in the last 16.