AceShowbiz -

Taylor Swift invited very, very special guests to help her bring her five-day concert at Los Angeles' Staples Center to a close on Wednesday night, August 26. The 25-year-old pop superstar surprised the sold-out crowd packing the venue when Justin Timberlake and Selena Gomez made unexpected appearances during the show.

"This has been so hard to keep a secret. Anyone who knows me knows this is my favorite artist," Swift, who's openly been a huge fan of Timberlake, said when introducing him. She then brought him out for a duet of his 2013 hit single "Mirrors".

The ultimate special guest for the final night..... @jtimberlake with @taylorswift13!!! #1989TourLA pic.twitter.com/pxwMYFZjCy

— STAPLES Center (@STAPLESCenter) August 27, 2015

That night marked the former NSYNC member's first time to perform onstage since welcoming his and wife Jessica Biel's son Silas back in April. After their performance, Swift said that she's "so honored that this was his first performance back."

She continued, "He has given me so many incredible pieces of advice... I just am so happy he would dedicate his night to coming out and playing for you guys. He's just the best - that's why he's my favorite."

Gomez, meanwhile, came out as Swift's first special guest earlier that night. The former Disney princess teamed up with her BFF/"Bad Blood" video co-star for the first live rendition of her newest single, "Good for You".

Taylor Swift special guest number one for night five...... SELENA GOMEZ!!! #1989tourla @selenagomez @taylorswift13 pic.twitter.com/PdLdreU8qK

— STAPLES Center (@STAPLESCenter) August 27, 2015

Another name joining Swift on the stage was Lisa Kudrow who appeared as Phoebe Buffay, her character from "Friends". "This girl, she's only ever played in coffee houses before," the songbird said before welcoming Kudrow and performing Phoebe's song "Smelly Cat".