Decked out in a curve-hugging red dress, Johansson joked about there not being a lot of pressure being host, even if the show ends up being bad.
"What are they going to do? Fire my fiance?" Johansson said. "Oh no, what are we going to do without his paycheck?"
The monologue quickly sidetracked into bizarrely dated territory when several cast members are turned to dust with a Thanos-like snap.
"Why is this happening?" Beck Bennett asked desperately, to which Johansson said it must be Thanos.
"No, I mean this monologue. It doesn't seem super topical?" Bennett said. "Was this like, a back-up monologue from the last time you hosted?" However, his line of questioning was quickly cut off when he got turned to dust as well.
She was then joined on stage by Michael Che and Jost, who she didn't seem super excited to see. When her fiance asked why her relief at him still being alive was somewhat lackluster, Johannson said, "I'm just focused on Thanos right now."
After being joined by Kenan Thompson playing Nick Fury (but also still just mostly playing himself), they discovered that it wasn't Thanos who snapped half the cast out of existence. Rather, it was Pete Davidson, who bought the actual infinity gauntlet online.
After some persuading, Johansson got Davidson to snap the cast back into reality, which also led to a hilarious exchange between Davidson and Thompson, who asked the young comic about the fact that he's managed to take a few weeks off this season.
"When you've been here as long as I have, you can do that," Davidson said.
"Really? Well that's good to know!" Thompson -- who's been on the show for 17 seasons -- said angrily.
Johansson then joined the entire cast -- including her fiance -- on stage, and the pair smilingly embraced as she gushed about all the great times she's had on the show.
"I just want to say that this place means so much to me," Johansson said, beaming. "I've made so many friends here, and I met the love of my life here."
The pair then exchanged a very sweet kiss as they got a cheer from the cast.