Matthew Morrison & JC Chasez: 'This I Promise You'!

Matthew Morrison hits the stage on Monday (June 13) at the Hammersmith Apollo in London, England.

The 32-year-old Glee actor brought out a special guest for one of the songs on his set list – JC Chasez!

Matthew and JC performed the *NSYNC ballad “This I Promise You” – check out a video of the performance below!

“Just finished my first concert in London. Thank you to everyone who came out tonight! A dream come true for me!” Matthew tweeted, adding, “Thank you JC Chasez for coming on stage last night. You rocked it! Also, thanks Josh Bray for opening the show!”