Critics from all over the political spectrum and many journalists blasted the "Today" show host for being out of his element during the broadcast.
"How can someone like (Matt Lauer) not set the record straight on Trump's bogus claim of being against the war in Iraq?" wrote Washington Post's fact checker Glenn Kessler.
"I hate media-on-media violence, but Trump's support for the invasion of Iraq has been rather well documented. No Lauer follow-up?" Yahoo News' Olivier Knox tweeted.
While Trump supporters claimed that Lauer disrespected their candidate, other viewers said the host repeatedly interrupted Clinton and never once interrupted Trump.
New York Times columnist Nicholas Kristof wrote that the forum was "an embarrassment to journalism."
As The New York Times pointed out, other moderators could run into similar issues when the formal presidential debates begin later this month, especially with Trump.