The sixth-seeded Berdych had his third break point of the match — after converting the previous two — but he put a backhand into the net after a long rally with Nishikori on the defensive.
Berdych attributed the loss of the match to the loss of that point.
“The rally starts pretty well for me, but I was not able to break him. Then I lost my serve,” said Berdych, who has already been defeated twice this week. “Basically, that was it. That was the difference today.”