Gregan's iconic tackle on Wilson effectively won the Bledisloe Cup for the Wallabies in 1994 and propelled him to rugby superstardom.
McMahon saves Wallabies with massive hit VIDEO: Wallabies forced to play rugby league
McCalman won't get the same recognition but his cover tackle on Wales centre George North should not be forgotten as Michael Cheika's men prepare to tackle the knockout stage.
The Wallabies were reduced to 13 men after Will Genia and Dean Mumm were sin binned in the 57th and 60th minutes.
Having already defended their line for several minutes and clinging to a 12-6 lead, McCalman pulled off this try-saver on the massive Wales centre to stop the Wales taking the lead less than 15 minutes from full-time.
The tackle that broke Wales' spirits! pic.twitter.com/o5NIBcmnJA
— Sportal (@SportalAU) October 10, 2015
Bernard Foley and prop Scott Sio also deserve credit but McCalman was the real hero.
A couple of minutes later Adam Ashley-Cooper pulled off a key turnover as the Wallabies got out of their own end as they held on for a gutsy 15-6 victory.
With the win the Wallabies secured a quarter final showdown with Scotland next Monday (AEDT).