Jay Leno, Jimmy Fallon Walk Down Memory Lane Together

Late-night hosts share something in common from "Tonight Show" debuts.

ByABC News
February 4, 2014, 1:42 AM

Feb. 4, 2014— -- If you want to host the “Tonight Show,” you might want to start wearing a three-piece suit.

Jay Leno and Jimmy Fallon, the current and future “Tonight Show” hosts, shared the spotlight on Monday’s episode, discussing their respect for each other – and comparing vintage outfits.

Leno has hosted the program for two decades. Fallon, who begins his turn as the show’s host on Feb. 17, served as Leno’s guest Monday. Fallon has hosted “Late Night,” which airs directly after Leno’s program, for the past five years.

During Monday’s episode, Leno aired footage from Fallon’s first appearance on the program – Sept. 5, 2002. He was there promoting his comedy album “The Bathroom Wall.” Other guests included Penn Badgley, Kelly Clarkson and the Dixie Chicks.

Fallon, then 27, was wearing a three-piece suit during that appearance, blanketed by the excess material. His hands shook, nervous and jittery.

More than a decade later, Fallon squirmed as the video aired.

“I look like a banker on ‘Little House on the Prairie,’” he said Monday.

Leno then showed a photo from his own first guest appearance on the program – March 2, 1977. For the segment, Leno wore a mint three-piece suit, riffing on newscasters, directory assistance and winter cold.

“You look like a stylish leprechaun,” Fallon joked of his predecessor.

Leno’s Monday monologue poked fun at Fallon’s appearance, saying Fallon was visiting, “to help me pack.”

“Y’know, Jimmy starts as the new host of ‘Tonight Show’ on the 17th. It would be strange if there was some accident and he was not able to … fulfill his duties as host,” Leno said.

As Monday’s show continued, the mood turned to back-patting. Fallon took part in his popular “Late Night” segment “Thank You Notes,” writing missives to his mentor.

“Thank you, Jay Leno,” Fallon said.

“I will do my best to make you proud.”

After “Tonight Show” musical leader Rickey Minor played the opening notes to the “Thank You Notes” background music, Fallon inquired about his employment status.

“What are you guys up to in two weeks?” Fallon asked. With the show moving from California to New York City, current staffers will effectively be losing their jobs, encouraged to apply for spots on the new program.

Only three episodes remain in Leno’s 22-year “Tonight Show” tenure. Conan O’Brien previously succeeded Leno in 2009, but Leno returned to lead the show one year later.

Leno’s final show is slated for Thursday, with guests Billy Crystal and Garth Brooks.