In the post-DC Comics Relaunch universe of SUPERBOY BIG GULP:
Unaware that his SLASHPOINT self was getting all 'slashy' with long-lost bud, Barry Allen, GREEN LANTERN HAL JORDAN was the second hero who tried to set-up shop next door to the DCU.
Having duped the dudes at MARVEL's border with a fake green card, Hal thought he was home free. Better yet, with FEAR ITSELF sweeping across the Marvel U, Green Lantern knew he'd quickly earn his place by defeating any fearful foe he felt he'd face.
Until his own face had an unfortunate meeting with CAPTAIN AMERICA's fist, that is.
Cap, you see, had heard about the ring-slinger; he knew DC's cosmic cop was there to set up his green space cop shop. And if anyone could cripple Cap's plans of booting BUCKY out of the picture to protect his own, it was Green Lantern.
And so, fist met face, and Green Lantern's high hopes of becoming Marvel's hot new hero went the way of WONDER WOMAN.