CNN’S headline-grabbing GOP town hall last night became the most watched of the genre in cable news history, both in overall audience and in the news demo. The network finished No. 1 in primetime each hour among cable news nets, outstripping the combined delivery of Fox News Channel and MSNBC.

An average of 3.3M viewers watched as the three remaining GOP candidates. Interest was high because, just hours earlier, Donald Trump’s campaign manager Corey Lewandowski turned himself in to police in Florida after being charged with battery for allegedly grabbing and yanking former Breitbart reporter Michelle Fields during a Trump rally as she attempted to buttonhole him for a question. Naturally, host Anderson Cooper asked all three candidates about that. Trump defended Lewandowski, explaining to Cooper that Fields’s pen might very well have been a bomb.  But the best line of the night was Cooper telling Trump, “With all due respect, That’s the argument of a five-year-old” after Trump opted for a he-started-it response to a question about re-tweeting an unflattering photo of Ted Cruz’s wife next to one of his former model wife Melania.

“I didn’t start it – no it’s not,” Trump, who wants to be the leader of the free world, responded to Cooper’s behaving-like-a-five-year-old observation.

“The argument of a five year old is, ‘He started it’,” Cooper explained patiently. At a town hall. To a man who would be President of the United States.

“Excuse me. You would say that. That’s the problem with our country,” Trump replied, taking the high road once again.

Meanwhile, Ted Cruz declined to say he’d keep his pledge to support the GOP candidate if it’s Trump, during his town hall appearance; Trump returned the favor, and a really good time was had by viewers.

Meanwhile, FNC logged 2M viewers and MSNBC 1.2M.

In the news demo, CNN clocked 1.1M viewers, besting combined FNC (422K) and MSNBC (292K).

FNC had attempted to make a big counterprogramming play last night. It booked a Lewandowski interview with Eric Bolling, who was subbing for Bill O’Reilly on The O’Reilly Factor; a Fields interview with Megyn Kelly on The Kelly File, and a Trump interview with Sean Hannity on Hannity. But, after the bookings were confirmed and FNC  announced the “gets” on air, Corey Lewandowski and Fields each pulled out of the commitments.