Pablo Sandoval is WAYYY ahead of the game ... surprising his girlfriend with a $140,000 pre-Valentine's Day gift ... and it all went down live on "TMZ Sports."
The Boston Red Sox 3rd baseman FaceTime'd in from The Auto Firm in Miami -- where he commissioned car god Alex Vega to hook up his lady with a killer custom vehicle.
Her reaction is priceless -- and you can see the whole thing on "TMZ Sports" on Friday at 9 PM PT, 12 AM ET on FS1.
Cupid would be proud.