stopped play in the middle of his second-round clash with Daniil Medvedev when the automated system failed to call a ball long. Electronic line-calling has been introduced on the clay this year in an effort to provide consistency and clarity on whether a ball has landed inside the lines, but the system failed in Rome on Friday.

Norrie immediately stopped the point and circled the mark on the clay, waving his arms in disbelief when no call of 'out' came. Players can no longer overrule the automatic calls but the umpire stepped in to make an announcement when he realised the audio malfunctioned.

The British No. 3 was right to assume Medvedev had sent the ball long. Chair umpire Renaud Lichtenstein received a message via his walkie-talkie, being informed that the automated hawkeye system showed the ball was out, even though a call never came.

It came at a crucial moment as Norrie had a break point on the 10th seed's serve while trailing 1-4 in the second set. And he secured the break when the chair official confirmed the call, giving the point to the Brit.

"Ladies and gentlemen, the system didn't call the ball, we didn't have the audio, but they're going to show the result of the ball, and the ball was out. Game, Norrie," Lichtenstein announced to the fans on the Pietrangeli court.

Sky Sports commentator Jonathan Overend was pleased the umpire stepped in, fearing Norrie would have been left short-changed if Medvedev won the point.

"Good. Hugely relieved about that. The system did call it out but the audio just wasn't heard," he said.

"That could be anything, that could be a faulty lead going into the speakers. What a relief because if the system had called it on the line, but the ball mark had clearly shown it out."

It gave Norrie a lifeline after he had gone a double-break down in the second set, and he managed to close the gap with the former world No. 1.

But Medvedev was still too good for the Brit and he quickly broke again, going on to seal a 6-4 6-2 victory.

It's not the first time the new electronic line-calling system has come under question on the clay. During the recent Madrid Open, Alexander Zverev pleaded with chair umpire Mohamed Lahyani when he thought a shot from his opponent, Alejandro Davidovich Fokina, had gone wide.

The automated system called it good and Zverev urged Lahyani to get off his chair and look at the mark on the court, even if he didn't overrule it. But the umpire was not allowed to do so.

The world No. 2 then on his phone. After the match, Zverev .

"I honestly think that there was a malfunction in the system in that moment. That's why I went to the umpire and I said, 'Please, come down to have a look at this, I'm not crazy'. I can see what was happening," he said after the match.