Sunderland took the advantage in their Championship play-off semi-final against Luton with a 2-1 win in the first leg at the Stadium of Light.
Luton took a deserved victory in the the 11th minute when Elijah Adebayo fired in from close range following a bit of pinball in the box, which saw Alfie Doughty hit the post.
The hosts then struggled to response, but burst into life when Manchester United loanee Diallo curled in an impressive effort from distance to square things up just before the break.
The winner came when Trai Hume poked Jack Clarke's cross into the far corner of Ethan Horvath's goal.