The biggest upset at Wimbledon thus far took place during Day 5 action on Friday as Na Li was upset by Barbora Zahlavova Strycova. Despite a surprise challenge on match point by Li, which forced Strycova to replay the match point, Strycova won in straight sets - both of which went to tiebreakers. Here are the match stats.

Here is the first point in which Strycova thought the match was over before Li challenged it. The ball was originally called out:

On the replay of the point, Li Na double faulted, and Strycova got to celebrate a second time. 

She will play 16th-seeded Caroline Wozniacki in the round of 16. 

Meanwhile, Shuai Peng defeated American Lauren Davis and will face the winner of the Venus Williams/Petra Kvitova match in the round of 16. Peng lost the first set 0-6, but came back to win 6-3, 6-3 in the final two sets. Here is Peng's match point: