Republican US presidential nominee Donald Trump listens as Democratic nominee Hillary Clinton answers a question from the audience during their presidential town hall debate at Washington University in St. Louis, Missouri, US, October 9, 2016. [Photo/Agencies]

ST. LOUIS, the United States - In one of the nastiest US presidential debates in recent memory, Republican candidate Donald Trump went on the offensive Sunday night, but experts said Clinton showed a better command of policy matters.

In an event that looked more like two hungry sharks trying to devour each other, the candidates relentlessly went on the attack in the 90-minute debate at the Washington University in St. Louis, Missouri.

While Clinton spoke eloquently on a number of difficult foreign policy matters, Trump often appeared to take the offensive, tirelessly blasting Clinton on one issue after another, from foreign policy to healthcare, to the economy, and to inner cities.

Dan Mahaffee, an analyst with the Center for the Study of the Presidency and Congress, told Xinhua that Trump's performance exceeded the low expectations that many had before the second debate.

Many people did not expect Trump to win the debate as the attention was shifted to the newly released tapes of Trump's making sexist remarks about women more than a decade ago.

Trump avoided the mistakes he made during the first debate, but Clinton still demonstrated a better command of the issues and a more presidential temperament, Mahaffee said.

While Trump avoided the gutter, he yet failed to answer his taxation issues and opened a huge gap with Clinton on foreign policy as he said that Russia, Iran and Syrian President Bashar al-Assad were really the ones fighting the Islamic State (IS) group, Mahaffee said.

Still, Trump shocked some analysts when he threatened to jail Clinton, which was deemed inappropriate in the United States.

"Finally for Trump, the statements about using prosecutors and powers of the Presidency to investigate Clinton if he were to be elected reminded many of dictatorships rather than candidates for president," Mahaffee said.

While Clinton did well and spoke well on foreign policy and complex policy issues, as she usually does, she was unable to deliver a killer blow to shut down Trump. While she dominated Trump in the previous debate, she was unable to do so this time.

"Clinton did well during the debate, but when it is an election where there are concerns about her energizing her side of the electorate, she didn't seem to find a knockout blow or memorable moment," Mahaffee said.

Clinton may have been too passive expecting that Trump would trip himself up, Mahaffee said.

"Trump has used much of this debate to fire up the Trump base, but that brings him 30 or 40 percent of the electorate. He seems to have abandoned people who want a way forward, and may have imperiled a lot of down-ballot Republicans," he added.

Darrell West, vice president and director of governance studies of the Brookings Institution, told Xinhua that Trump was not contrite in this debate, referring to his recently aired lewd sexist remarks about women.

"He tripled down on many of his past statements. He claimed (Hillary Clinton's husband and former President) Bill Clinton is a rapist. He threatened to put Hillary Clinton in jail. This may help him with his base, but not with undecided voters. I don't think Trump helped himself expand his support," West said.

Clinton "showed more leadership" on the direction of the country, he said.

"Clinton condemned Trump's insults and presented a positive vision for the country. She criticized him for not paying federal income taxes and defended Obama's healthcare program," West said.

Clinton did a better job than Trump in expanding her support, because she showed that she is more knowledgeable and displayed a good temperament.

"I don't see a path to victory for Trump given his lewd comments and failure to pay federal income taxes," West said.