Wimbledons under-fire line technology system suffered another embarrassment during Taylor Fritzs quarter-final win over Karen Khachanov on Tuesday.
Swedish umpire Louise Azemar Engzell had to stop a point in the opening game of the fourth set on Court One when fault was incorrectly called after a Fritz forehand landed well inside the baseline.
The call of fault, rather than out, and positioning of the ball suggested the system was still tracking Fritzs serve as opposed to a rally and the point had to be replayed.
Tournament organisers said on Sunday they were confident of avoiding further issues with the technology after a major error in Sonay Kartals fourth-round defeat to Anastasia Pavlyuchenkova in the womens draw.
On that occasion, the new system failed to call out when a shot by Kartal landed well behind the baseline.