The celebration for Mookie Betts might never stop ... 'cause on top of winning the World Series two weeks ago -- the Red Sox superstar just welcomed a baby girl into the world!!
The outfielder posted Tuesday he and his longtime girlfriend, Brianna Hammonds, had their first child together ... and said he couldn't be more pumped about it.
"Never knew what unconditional love meant or how it felt until I met this little princess," Betts wrote.
"Nov 6th 2018 is a day I’ll never forget❤️"
It's been a helluva past few days for Betts ... who won a 'ship on Oct. 28, celebrated like crazy at nightclubs, had an epic parade around Boston -- AND partied with Tom Brady and the Pats last weekend.
Things might still be gettin' better for Mookie too ... he's expected to be named AL MVP next week!!