UPDATE: In updated “live plus same-day” fast national estimates from Nielsen released Thursday morning, CBS’s premiere of “The Late Show with Stephen Colbert” averaged 6.6 million viewers, marking Tuesday’s most watched late-night program.

Colbert trumped the competition with Jimmy Fallon’s “Tonight Show” pulling in 2.9 million viewers on NBC, and ABC’s “Jimmy Kimmel Live” averaging 1.75 million viewers.

Comparing Colbert’s bow to past late-night debuts, Jimmy Fallon opened to 11.3 million viewers in Feb 2014, though he had a lead-in from the Winter Olympics and his start time was pushed back to 12:05 a.m. ET.

Stephen Colbert opened big on his first night at the helm of CBS’ “The Late Show.”

In Nielsen’s 56 overnight metered markets, which cover about 70% of U.S. TV households, Tuesday’s hourlong-plus telecast averaged a 4.9 household rating/13 share. It easily dominated the late-night competition and marked a 123% increase from “The Late Show’s” season premiere last year in David Letterman’s final season as host.

NBC’s “The Tonight Show with Jimmy Fallon” dropped to second place with a 2.4/6 while ABC’s “Jimmy Kimmel Live” delivered a 1.4/4.

“The Late Show” ran six minutes long in its inaugural outing. The big turnout for Colbert’s launch gave a lift to its 12:35 a.m. companion “Late Late Show with James Corden.” Corden’s hour delivered 1.3/5, elbowing past NBC’s “Late Night with Seth Meyers” (1.1/4)

More detailed ratings information for “The Late Show” will be available later today.