The one time when Invincible met Peter and the New Avengers (post-Avengers Disassembled) in the Marvel Universe.
[and no Mark isn’t an MU character, this was the first story takes place during the events of Invincible #33.]
Marvel Team-Up Vol. 3 #14 (November 2, 2005) - Spider-Man meets Invincible
Written by: Robert Kirkman
Artist [pencils & inks] by: Cory Walker
Colorist by: Bill Crabtree
Lettered by: VC’s Cory Petit
Edited by: Tom Brevoort (editor), Andy Schmidt, Molly Lazer & Aubrey Sittersono (assistant editors)
Published by: Marvel Comics