Worthington took the stage with Alabama for "Mountain Music," and sang Kenny Chesney's "Summertime" with Kat Perkins, Audra McLaughlin, Kristen Merlin, Ryan Whyte Maloney and Morgan Wallen.
Grimmie performed with Ed Sheeran for a stripped-down rendition of "All of the Lights," and reunited with Bria Kelly, Tess Boyer and Jake Barker for Lorde's "Team."
Kaufman sang "Get Her Back" with Robin Thicke, and brought back TJ Wilkins, Stevie Jo and Sisaundra Lewis for "Am I Wrong" by Nico & Vinz.
Top-20 male singers Wallen, Jo, Barker, Delvin Choice and Patrick Thomson also sang Hall & Oates' "She's Gone," and female finalists Boyer, Dani Moz, Deja Hall, Madilyn Paige and Melissa Jimenez sang Rihanna's "Umbrella."
Even more so, the star-studded episode began with in-house songwriter Ryan Tedder's OneRepublic single "Love Runs Out." Justin Moore also stopped by to sing "Lettin' the Night Roll,' Tim McGraw touted "City Lights," Coldplay introduced their new single "A Sky Full of Stars," and Sheeran performed "Sing."
After last words from the top three singers, the season six winner was finally named: Kaufman. Worthington came in second place, and Grimmie came in third. Kaufman's victory means that Usher nabbed his first "Voice" coach victory as well.