Moderator Lester Holt, anchor of NBC Nightly News, asks a question of Hillary Clinton during the presidential debate at Hofstra University in Hempstead, N.Y., on Sept. 26. (Joe Raedle/AP)

Lester Holt started out with a joke at his own expense.

“The thud you heard backstage was the sound of my knees buckling,” he told the studio audience (and about 100 million other people), ready to watch the first presidential debate at Hofstra University on Monday night.

After that, and a few moments of setup and his first question, Holt seemed to almost disappear from view as the debate devolved briefly into a yelling match. He was so unobtrusive early on that observers joked on social media that they needed to put out an all-points bulletin for the NBC anchorman.

Later, he reemerged and took charge more, although never with a great deal of strength or control. On the bright side, Holt was dignified, didn’t call undue attention to himself and kept the debate flowing.

It really wasn’t that bad — it was a middling performance on a tough assignment.

Here are the key moments from the first 2016 presidential debate between Hillary Clinton and Donald Trump on Sept. 26. NBC Nightly News anchor Lester Holt moderated the debate at Hofstra University in New York. (Sarah Parnass/The Washington Post)

Holt’s biggest win was in challenging Donald Trump on claims about how he opposed the Iraq War from the start, on the constitutionality of the policing practice known as “stop-and-frisk,” and on whether an IRS audit prohibited the release of tax returns. (He didn’t. It isn’t. It doesn’t.)

Holt’s worst moments came at a few points when Trump was shouting over Hillary Clinton’s answers, and the debate seemed to be turning into a high-decibel wrestling match without a referee.

At 9:25 p.m., I made this note: “Out of control. They’re just yelling at each other.”

Holt made a small effort: “Let me interrupt. . . .” But no one seemed to hear him, and Trump in particular was in full rant, with Clinton trying to get in a few words.

When this stunning word volley slowed, Holt looked a little shaken. “We’re unpacking a lot here,” he said. Yes, we were unpacking everything in the house, and the entire contents of the scary neighbor’s garage, too.

But onward!

Washington Post reporter Dan Balz breaks down the first presidential debate between Hillary Clinton and Donald Trump. (Dalton Bennett/The Washington Post)

A few minutes later, Holt began to assert some control. After Trump gave a disingenuous answer about his tax returns — again making the excuse that he was being audited — Holt popped his head back into the room. He noted that a tax audit wouldn’t prohibit the release, and then he admonished the live audience for cheering a Trump line about Clinton’s deleted emails.

But it was Clinton who more firmly and effectively fact-checked Trump on his taxes, listing all the reasons that he might not want the public to see them.

The role of the moderator has been widely discussed over the past two weeks, ever since Fox News’s Chris Wallace asserted that he had no plans to “truth-squad” the last debate, which he will moderate.

My position has been that the moderator must make sure that the truth gets out — if not from the other candidate’s rebuttal, then by taking the reins himself.

Holt seemed to want to take a moderate stand on this, to assert the big truths while not calling undue attention to himself. He did that reasonably well.

He certainly passed the test of not making the debate about himself. Far from it, in fact. He was too weak, at times, to keep the debate under control.

And although his truth-squad efforts fell short, he didn’t have to do too much because Clinton was able to do it herself, quite effectively in most cases.

One final telling moment — for all three of those onstage — came when Holt asked about Trump’s infamously sexist comments on women’s appearance, and whether Clinton has a “presidential look.” Trump quickly, and again disingenuously, changed the subject to Clinton’s stamina, not her appearance.

Holt tried to correct him — “The quote was, ‘I just don’t think she has the presidential look’ ” — and Trump simply rolled right over that. But Clinton turned it to her advantage, reeling off her accomplishments and schedule, and for a moment at least, there was a beat of silence.

The task was nearly over. Holt managed to get a promise from each candidate that they would support the results of the election, no matter what. Holt wrapped it up, looking extremely relieved and in need of a stiff drink.

You couldn’t call it a masterful performance. But it wasn’t terrible or career-damaging, either.

I give it a solid B-minus.

For more by Margaret Sullivan visit wapo.st/sullivan.