NBA guard Nik Stauskas just took the biggest shot of his life ... and SCORED -- 'cause his smokin' hot girlfriend said yes to marriage!!
The new Trail Blazers stud just met Alexandra Brynn last August ... but things heated up quickly -- with Nik popping the question Wednesday in front of EVERYONE at Philadelphia's Rittenhouse Square.
And, yeah ... the ring is definitely NBA sized.
"Words can’t even describe the feeling I had waking up this morning knowing I’d be waking up next to you every day for the rest of my life," Nik said on his IG page.