Justin Bieber — Takes Mystery Girl to NBA Finals … DAYYYUM!! [PHOTO]

0621_justin_bieber_mystery_girl_SplashJustin Bieber tried to impress his Miami mystery date by taking her to Game 7 between the San Antonio Spurs and Miami Heat — but based on some pics he screwed it up.

It”s unclear if things are serious with this new chick — who seems older than Selena Gomez, and definitely more endowed than SG.

JB was spotted around Miami with her before the game … and sitting next to each other in a luxury box during.

Here”s the thing … if Justin really wanted to impress her, he wouldn”t have worn those neon sneakers.