Jimmy Kimmel's post-Oscars show featured dozens of celebrity cameos, YouTube influence, an appearance by Toronto mayor Rob Ford, an inspired selfie and the spirit of a late-night TV legend.

"House of Cards" star Kevin Spacey provided the biggest laughs, showing off his humor by imitating "Tonight Show" icon Johnny Carson.

"The big picture tonight, I haven't seen it, it's called '12 Years a Slave' … I assume it was about my first marriage," Spacey said, riffing on Carson.

Kimmel explained his own personal "connection" to Carson - during the 1980s, he appeared on an episode of "Tonight Show" as a teen magician. He's never been able to track down a video clip, he said.

Spacey, who narrated a PBS documentary about Carson's life, said he has the clip - and that it's posted on his website, kevinspacey.com. Within moments of the announcement, the site crashed, flooded by the surge in traffic.

The site was back within an hour, showing a spoof video of Spacey as Carson - wearing a checkered blazer with gray in his hair - and Kimmel, with a mullet wig, braces and glasses.

Something else the pair did sparked a wave of attention online - a selfie showing Spacey giving a thumbs up as Kimmel smiled behind him.

Let's beat @TheEllenShow selfie w @jimmykimmel #photobomb pic.twitter.com/N5qsk9TfaF

- Kevin Spacey (@KevinSpacey) March 3, 2014

The pair vowed to top Ellen's star-studded selfie from the Oscars (Spacey is in that back row for that photo), which set the all-time record with more than 2 million re-tweets by Monday morning.

Spacey's selfie? A bit short, with 20,000 re-tweets following the show's airing.

Midway through the episode, Toronto mayor Rob Ford emerged, ready for his interview.

"You're on the show tomorrow night," Kimmel said.

"Oh, sorry," Ford responded, returning to the shadows.

Kimmel's post-Oscars specials are known for their celebrity-crammed movie trailers, including 2012's "Movie: The Movie," which showed a meteor headed toward earth.

This year, instead of one clip, the episode featured four, all of them riffing off of YouTube sensations.

Brothers Chris and Liam Hemsworth starred in "Bitman Begins," a send-up to the 2007 viral video "Charlie Bit My Finger - Again."

Queen Latifah served as a time- and space-traveling sage in "Sweet Brown: Ain't Nobody Got Time For That."

Spacey personified "Keyboard Cat" in "Ameowadeus," with appearances by Christoph Waltz, Gary Oldman and Ben Kingsley.

And Joseph Gordon-Levitt starred as "David After Dentist" alongside Catherine Zeta-Jones, Samuel L. Jackson and Seth Rogan, acting as the boy in the back seat who rambled after receiving anesthesia.