Pete Wentz got murdered ... so did Lil Yachty and Joel McHale -- and it was TOTALLY AWESOME!!!
They were all part of a huge celebrity Fortnite Pro-Am tournament at E3 on Tuesday ... where pro gamers were teamed up with other celebs and the top winners got $1 MILLION for charity.
The big winners were the duo of Ninja and Marshmello ... who beat out teams like CouRage JD and NBA star Kenneth Faried (they finished 2nd and scored a $500,000 prize).
Pete Wentz did pretty well too ... the rockstar and his teammate, Ali-A, finished in 5th place and won $80k for charity.
Other stars in the event included NBA stars like Paul George and Andre Drummond, NFL stars like Tarik Cohen, musicians like Ty Dolla $ign and PARTYNEXTDOOR.
Even Backpack Kid was there!
Check out the gallery and make sure to brush up on your gaming skills -- remember, there's like $100 MILLION in Fortnite money up for grabs this season!