LONDON (AP) — A malfunction with Wimbledon 's new electronic line-calling system required a point to be replayed during a quarterfinal match between Taylor Fritz and Karen Khachanov on Tuesday.

The issue occurred during the opening game of the fourth set on Court No. 1 after Fritz had served at 15-0 and the players exchanged shots. Then came a “fault” call.

Chair umpire Louise Azemar-Engzell stopped play and a few moments later ordered the players to “replay the last point due to a malfunction."

The system had tracked Fritz's shot in the rally as if it was a serve, the All England Club said.

“The player’s service motion began while the (ball boy/ball girl) was still crossing the net and therefore the system didn’t recognize the start of the point. As such the chair umpire instructed the point be replayed,” the club said in a statement.

Khachanov won the replayed point but the fifth-seeded Fritz advanced to the semifinals with a 6-3, 6-4, 1-6, 7-6 (4) victory.

Wimbledon switched this year to the electronic system that replaced human line judges but it's been anything but smooth.

On Sunday, there was a glaring mistake at Centre Court during Anastasia Pavlyuchenkova’s three-set victory over Sonay Kartal in the fourth round. A shot by Kartal clearly landed past the baseline but wasn’t called out by the automated setup — called Hawk-Eye — because it had been shut off.

On Monday, club officials blamed “ human error ” for the oversight. Club chief executive Sally Bolton said the technology was “inadvertently deactivated” by someone for three points in the match.

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AP tennis: https://apnews.com/hub/tennis