Presidential debate: Trump criticises moderator Lester Holt

The Republican also complained about his microphone crackling and being at a lower level than his opponent's.

After an often bitter exchange, Mr Trump said he "might hit her harder" in the next televised debate.

Overnight polls with small samples were split on who won, but more rigorous surveys are due in the coming days.

Although Mr Trump told reporters immediately after the debate that Lester Holt had done a good job, he accused him of a left-leaning performance the next morning.

"He didn't ask her about the emails, he didn't ask her about the scandals, he didn't ask her about the Benghazi deal. He didn't ask her about a lot of things he should have asked her about. Why? I don't know," he told the US news programme Fox and Friends.

Profile: Who is moderator Lester Holt?

Presidential election debate: All our best material in one place

He said Mr Holt had been much tougher on him: "You watch the last four questions, he hit me on birther [Mr Trump's past allegation that President Obama was not born in the US], he hit me on a housing deal from many years ago, that I settled on with no recourse and no guilt... that's a beauty to be asked, a 40-year-old lawsuit."

He also said his microphone was "terrible" and crackled, and that his volume was lower than Hillary Clinton's microphone. He blamed this for what some listeners thought were sniffles by Mr Trump during the debate.

Asked to rate Hillary Clinton's performance, he said he would give the Democrat a C-plus, but declined to grade himself. "I think I really did well when they asked normal questions," he said, but added he naturally struggled when asked "unanswerable" ones.

On what he might do differently, he said: "I really eased up because I didn't want to hurt anybody's feelings. So I may hit her harder in certain ways."

US debate: Five Twitter takeaways

Key issues - where candidates stand

How does the US election work?

Debate highlights

Much of the debate centred on personal issues and attacks, with both candidates saying the other did not have the right character or temperament to become president of the United States.

• Mrs Clinton said her rival was the kind of man who can be provoked by a tweet and should not have his fingers anywhere near America's nuclear codes
• Mr Trump said Mrs Clinton did not have the stamina to be president
• He promised he would release his tax returns if she released 33,000 deleted emails from her private email set-up while secretary of state
• She said there were no excuses for her "mistake" in the private e-mail server, and that she takes responsibility for it
• African-Americans are living "in hell" in the US due to gun violence, Mr Trump said
• Mrs Clinton criticised him for saying climate change was a Chinese hoax
• He attacked her for being weak on Islamic State militants: "You've been fighting Isis your entire adult life.''
• Mrs Clinton attacked Mr Trump's long-held belief that President Obama was born outside the US, accusing Mr Trump of having "a long record of engaging in racist behaviour".
• In a wider assault on his treatment of women, she said he had called women "pigs, slobs and dogs"

What they didn't say in the first debate

Watch full debate (via digg)

Role of gender in the debate

What do the polls say?

A CNN/ORC poll taken after the debate found that 62% of voters who had watched the head-to-head thought that Mrs Clinton came out on top, with just 27% giving it to Mr Trump.

This is based on interviews with 521 registered voters chosen as part of a random national sample. But only 26% identified themselves as Republicans while 41% identified themselves as Democrats.

An informal CNBC poll on its website found that 61% of people thought that Mr Trump won while 39% went for Mrs Clinton, but as CNBC itself points out, the poll is not scientific - anyone, including people outside the US, appears to be able to vote.

A post-debate survey by Public Policy Polling of 1,002 debate-watchers found that 51% of national voters thought Mrs Clinton had won, with 40% choosing Mr Trump and 9% undecided.

Who's ahead in the polls?

The US media view

New York Times - The editorial board was unimpressed with the debate, saying "when just one candidate is serious and the other is a vacuous bully, the term loses all meaning". Opinion writer Nick Kristof said Trump had "hurt himself", others said Mrs Clinton had "crushed" her opponent.

Fox News - Pundits said Mr Trump had "struggled", "never took control" and "failed to exploit" the issue around Mrs Clinton's emails. "It helps to be prepared," one writer told the Republican candidate.

Breitbart - Writers at the hard-right news website said Mr Trump had "bludgeoned" Mrs Clinton on trade and accused Lester Holt of "shilling" for Mrs Clinton. Some 75% of readers said Mr Trump had won.

New York Daily News - The tabloid's verdict: "A grumpy loser! Trump pesters, interrupts Hillary throughout debate - but Clinton gets the last laugh."

US media verdict on debate

And the fact-checkers?

The much-vaunted role of fact-checkers in this debate was perhaps not as central as many expected it to be.

Mrs Clinton's denial that she had called the proposed Trans-Pacific Partnership the "gold standard" of trade agreements was called out by fact-checkers, as was Mr Trump's denial that he had called climate change a hoax invented by the Chinese.

Reality Check: Clinton v Trump debate