Lleyton Hewitt was on the receiving end of some incredible sportsmanship on Tuesday night when Jack Sock conceded a point to let him know he should challenge a bad call.

Hewitt was trailing 4-5 in the first set of his Hopman Cup clash with the American when the chair umpire called the Aussie's first serve out.

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Lleyton was happy to take his second serve before Sock called out "That was in if you want to challenge it".

View photos Sock concedes Hewitt's serve was in. Image: Channel 7 More

Hewitt seemed stunned at such an amazing act of sportsmanship, while the crowd clapped and cheered the young US star.

View photos Hewitt reacts to Sock's admission. Image: Channel 7 More

The retiring Aussie hero trusted his opponent and asked for the challenge, with Hawk Eye showing the ball had indeed caught the line and was in.

View photos The successful challenge. Image: Channel 7 More

Hewitt went on to win the set and take the match 7-5, 6-4.

The No.26 ranked Sock appeared to gift Hewitt some easy points, with the Americans destined to lose the tie following Serena Williams' withdrawal.

The amazing moment immediately sparked memories of Tim Smyczek's similar act against Rafael Nadal at the 2015 Australian Open:







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