Ronda Rousey -- Hangin' w/ WWE Power Player

Seems Ronda Rousey is one step closer to making an official WWE cameo ... because the UFC champ was hangin' with one of the greatest wrestling managers in history this weekend.

Rousey and her crew (dubbed the 4 Horsewomen) hit up SummerSlam Sunday night in L.A. -- where they rubbed elbows backstage with Brock Lesnar's manager Paul Heyman.

Our sources tell us Rousey and Heyman got along great -- and Ronda (a huge wrestling fan) was stoked to meet the guy.

As we previously reported ... Rousey has expressed interest in a guest wrestler role at WrestleMania 31 in SF next year -- and she wants the 4 Horsewomen in her corner.

No word if Rousey and Heyman talked shop when they hung out this weekend -- but Heyman has worked with other UFC stars in the past (including Lesnar) so he could be the perfect guy to make Ronda's WWE dreams come true.

Don't worry UFC fans, we're told Ronda's #1 passion is MMA -- and she's not planning on giving that up anytime soon -- she's just a huge WWE fanatic and thinks a WWE cameo would be fun.