Ryan Garcia had a little good news/bad news sitch on his hands this week -- first, he's a father to a new baby ... plus, he's apparently leaving his wife who just delivered said baby.

The lightweight boxing phenom made shocking back-to-back announcements Friday evening, almost instantaneously ... namely, breaking happy news that he and his partner, Andrea Celina, had recently welcomed a boy into the world ... whom they named Henry Leo.

Within the hour of posting pics of his new kid -- which is actually his second with AC -- RG threw up a downer of a post ... in which he declared he and Andrea were getting divorced.

Ryan's birth post was jubilant, reading ... "Honored To announce my Beautiful First Born SON PRAISE THE LORD. I am so thankful, I love him so much already. He is so fast already haha. Took him just 8 min to arrive You know where he got that speed from lol. GOD DID! And GOD WILL ... THANK YOU LORD I LOVE YOU."

In a since-deleted IG post that went up almost immediately after the baby announcement, Ryan said he and Andrea were ending their marriage ... which was eye-popping for a couple different reasons. For starters, no one seemed to know they were already hitched.

Of course the bigger reason is ... it was literally the very next thing he posted.. Ryan wrote in part, "As I step into a new chapter in my life, it's with a heavy heart to share that Drea and I have decided to divorce." He goes on to say that they remain committed to co-parenting their two children, etc. Now, it's a bit unclear if he and Andrea are on the same page here.

Andrea herself did not post the divorce statement, and Ryan's now scrubbed it from his page -- even though it was publicly up for well over 12 hours. Andrea has since posted some cryptic messages of her own on her IG Story ... perhaps suggesting she's mad at him.

It's a strange turn of events ... especially considering they've been together since 2019. Now that Ryan's taken down his divorce announcement -- we're not quite sure where things stand.

We've reached out to Ryan's team for clarification and comment. So far, no word back.