Jimmy Fallon’s Monday debut on “The Tonight Show” was a ratings winner for NBC with 11.3 million viewers tuning in, according to figures from the Nielsen Company (NYSE:NLSN).

Fallon’s opening show, which featured Will Smith and U2 as guests, aired after the Winter Olympics, drawing two million more viewers than Conan O’Brien’s June 2009 debut audience of about 9.2 million.

Although Fallon’s debut fell short of the 14.6 million number that Jay Leno's latest goodbye episode attracted on Feb. 6, or the 11.9 million who watched Leno's first send-off in May 2009, Fallon's show got the largest audience in five years for a debut episode, and almost three times this season’s average of 3.9 million.

NBC reportedly said that Fallon’s “The Tonight Show,” which had cameos from Robert De Niro, Stephen Colbert, Sarah Jessica Parker, Mike Tyson and Joan Rivers, was up by 71 percent over his Feb. 6 “Late Night” farewell audience of 6.6 million.

Fallon’s success came at the expense of rivals such as David Letterman, who only garnered 2.4 million viewers, while Jimmy Kimmel drew in 2.1 million viewers.

“I really don't know how I got here," Fallon, who rose to fame as a cast member on “Saturday Night Live” told Monday night's cheering studio audience.

"I just want to do the best I can, and take care of the show for a while. If you guys let me stick around long enough, maybe I'll get the hang of it."