With a record of 18 match unbeaten and 18 knockouts, Anthony Joshua has never being beaten in a match before.
Anthony Joshua KNOCKED OUT in sparring session?
"Wach forced Joshua to go down, close to 8 seconds, but it wasn't anything serious," said a source who witnessed the session.
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However, reports indicate that the Nigerian-born British boxer was knocked out by sparring partner Marius Wach.
The 27-year-old has never been put down in the ring and onlookers at the BXR gym were said to have been astounded by what they saw.
"It's my first time of seeing Joshua gone down but he looked okay after that."
If true, it could be a cause for concern leading to Joshua's May 2 showdown with former world heavyweight champion Wladimir Klitschko in front of 90,000 people at Wembley on April 29.
Joshua's last fight came in December against Eric Molina, who he knocked out in the third round.
Klitschko, 41, hasn't fought since losing to Tyson Fury in November 2015. His overall record stands at 64 wins from 68 fights, 53 by knockout.
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