Justin Trudeau Trains with Black Boxing Champ Amid Blackface Scandal

Justin Trudeau is trying to fight his way out of his blackface scandal ... by stepping into the ring with a black boxing champion.

The embattled Canadian Prime Minister put on a pair of gloves, slipped into some boxing trunks and threw on a sleeveless shirt to spar with boxing champ Ali Nestor Wednesday, ahead of the leader's huge debate in his quest for re-election.

Justin looked like he got in a great workout with Ali, a retired boxer who now runs a non-profit geared toward helping disadvantaged youth. Trudeau got some boxing tips from Ali, but more than anything ... this seems all about optics.

As you know ... Trudeau is embroiled in controversy after photos surfaced showing him in blackface when he was 29 years old.

Trudeau's apologized for what he says was a racist lapse of judgment when he dressed up as Aladdin back in the day, but some Canadians have been calling for him to step down and bow out of the race ... and Al Sharpton told us Justin's mea culpa rings hollow.