Matt Lauer was behind the firing of top “Today” executive Jamie Horowitz after Lauer found out about a plan to replace his co-anchor Savannah Guthrie with Hoda Kotb, sources exclusively tell Page Six.

We’re told Lauer went to NBC News President Deborah Turness amid an anchor revolt sparked by rumors that, under a possible plan by Horowitz which had been discussed with NBC brass including Turness, Guthrie would be replaced by fourth-hour co-host Kotb and Natalie Morales could eventually be unseated as news reader by Josh Elliott.

An NBC source said: “Savannah, Natalie and Willie Geist heard about the plan and talked to Matt, who went to Turness and told her, ‘I want to keep these people,’ so she fired Jamie. Once again, Matt Lauer calls the shots at ‘Today.’ The idea of bringing Jamie in was to bring change to the show to help beat ‘GMA,’ but how can you fix it if nobody can make any changes?”

NBC announced Monday night that after weeks of turmoil at “Today,” Horowitz, a former ESPN programmer hired less than three months ago as general manager and SVP of the show to halt its ratings slide, was fired after what sources described as conflicts with staff, producers and NBC brass.

Horowitz, who has been on a “listening tour” taking in the opinions of “Today” staff and talent, was released from his job even before his official Dec. 1 start date.

NBC will have to pay Horowitz about $3 million for the remainder of his contract.

Turness held a 1:30 p.m. meeting Tuesday with “Today” talent to explain Horowitz’s abrupt departure. A source tells us of the meeting, “Some of the staff did ask, ‘Now what are we going to do to win?’”

When asked about the anchor uproar, Turness told us, “We have the best anchor team and the best show in morning television, and we are solely focused on the future.”