He then joined the cast of After Midnight -- including Patti LaBelle, Gladys Knight, Dule Hill and Fantasia -- for a spectacular song-and-dance number. Next, came a brief, breathless and hilarious monologue.
First, he teased those seated in the "mosh pit" below and behind him.
"You have the greatest view of the Man from Down Under's 'down under,'" he joked, singing, "Getting to know you..." and bending over to peek at the spectators from between his legs.
"Welcome to the Tonys. It is great to be back as your host. Tonight is a celebration of Broadway, the only place you can see Rocky in a boxing ring, Bryan Cranston in the Oval Office and Wolverine in tap shoes. You don't see this at Comic-Con, let me tell you," he said, referring to the superhero he plays in the X-Men film franchise.
Jackman then turned to former Tony Awards show emcee Neil Patrick Harris -- a current Best Actor in a Musical nominee -- who was sitting in the audience.
"He is a legendary, four-time Tony host, but Angela Lansbury has hosted five times, so Neil is right behind her and I was right behind him, which is still illegal in 13 states," Jackman quipped. "When they announced I was hosting tonight, Neil very generously texted me immediately, saying, 'Wow! That's fantastic!' I assume that's what 'WTF' means now, right?"
Harris, Idina Menzel and Sting are lined up to perform on the CBS telecast during which prizes honoring excellence on Broadway for the 2013-14 season will be handed out.
A Gentleman's Guide to Love and Murder went into the competition with a leading 10 nominations, while Hedwig and the Angry Inch followed close behind with eight nods. Up for seven awards apiece are After Midnight, Beautiful: The Carole King Musical, The Glass Menagerie and Twelfth Night. Bullets Over Broadway and The Cripple of Inishmaan are each competing for six prizes.
Bold-faced names left off the nominations list for the prestigious theater awards include Orlando Bloom for Romeo & Juliet, James Franco for Of Mice and Men, Ian McKellen and Patrick Stewart for Waiting for Godot and/or No Man's Land, Zachary Quinto for The Glass Menagerie, Daniel Radcliffe for The Cripple of Inishmaan, Denzel Washington for A Raisin in the Sun and Michelle Williams for Cabaret.
In the running for Best Musical are After Midnight, Aladdin, Beautiful: The Carole King Musical and A Gentleman's Guide to Love and Murder.
Shortlisted for Best Play are Act One, All the Way, Casa Valentina, Mothers and Sons and Outside Mullingar.
Nominated for Best Revival of a Musical are Hedwig and the Angry Inch, Les Miserables and Violet.
The nominees in the Best Revival of a Play category are The Cripple of Inishmaan, The Glass Menagerie, A Raisin in the Sun and Twelfth Night.