(NewsNation) — President Joe Biden and former President Donald Trump squared off in a heated debate filled with viral moments, including digs at one another and an argument over golf swings.

The CNN Presidential Debate is the first of two presidential debates as they head toward a rematch of the 2020 election.

Here are five viral moments from the night:

1) Biden stumbles through national debt topic: ‘We finally beat Medicare’

Early in the debate, Biden appeared to lose his train of thought while answering a question about the national debt.

He started out by saying Trump increased the national debt and blamed tax cuts on the wealthy for America’s economic woes.

Trump “had the largest national debt of any president in a four-year period,” Biden said. “Number two, that $2 trillion tax cut benefitted the very wealthy. What I’m gonna do is fix the tax system. For example, we have a thousand trillionaires in America. I mean billionaires. And what’s happening? We’re in a situation where they in fact pay 8.2% in taxes. If they just pay 24%, 25%, either one of those numbers we would’ve raised $500 million … billion dollars, I should say, in a 10-year period. We’d be able to wipe out his debt.”

“We’d be able to help make sure that all those things we need to do — child care, elder care, making sure that we continue to strengthen our health care system, making sure that we’re able to make every single solitary person eligible for what I’ve been able to do with the, uh, with the COVID. Excuse me, with dealing with everything we have to do with .. look, we finally beat Medicare.”

Trump responded, accusing Biden of “destroying Medicare” and Social Security by allowing immigrants to access those services.

Biden “beat it to death and he’s destroying Medicare because all of these people are coming in,” Trump said. “They’re putting them on Medicare. They’re putting them on Social Security. They’re gonna destroy Social Security.”

2) Trump: ‘I don’t know what he said’

Trump called out Biden for trailing off during his response on immigration policies.

“I really don’t know what he said at the end of this. I don’t think he knows what he said,” Trump said.

CNN’s Jake Tapper asked Biden why should voters “trust” him to resolve the crisis at the border, noting that a record number of migrants have crossed into the U.S. during his administration.

Biden pointed to the bipartisan border security deal and his recent executive order that limits the number of migrants coming across the border once the number hits a threshold.

He then appeared to stumble in thought before concluding.

“I’m going to continue to move until we get to total ban — on the total initiative relative to what we’re going to do with more Border Patrol and more asylum officers,” Biden said.

3) Biden says Trump has the ‘morals of an alley cat’

At the halfway mark of the debate, Biden brought up Trump’s conviction in connection with a hush money deal with adult film star Stormy Daniels.

Biden said Trump has the “morals of an alley cat” for allegedly having sex with Daniels while his wife, Melania Trump, was pregnant.

Trump pushed back, saying, “I didn’t have sex with a porn star, number one. Number two, that was a case that was started and they moved a high-ranking official at DOJ into the Manhattan DA’s office to start that case. That case is going to be appealed and won.”

4) Arguments over age, golf swings

Biden and Trump addressed concerns about their age, which led to an argument over golf swings.

Biden pointed to his early years as one of the youngest politicians and said now he is one of the oldest before pointing out that Trump is only three years younger. Biden pivoted to accusing Trump of tanking the computer chip industry by enticing companies to move overseas for cheap jobs. He pointed to efforts to increase computer chip manufacturing, creating jobs that don’t require a college degree.

Biden also attacked Trump for calling the U.S. a failing country, saying no president has spoken like that before, calling the U.S. one of the strongest countries in the world and saying America is trusted around the world.

Trump said he aced cognitive tests and claimed Biden refused to take any, saying he wouldn’t get through. He said he is in very good health and attacked Biden for not being good at playing golf. Trump claimed to be in as good shape as he was decades ago.

Biden suggested Trump is lying about his health and said he would be happy to play golf against Trump. The two sparred over golf handicaps before moderators intervened.

5) Trump: ‘I wasn’t going to run’

Trump said he will accept the results of the 2024 election “if the election is fair.”

“I wish he was a great president, I wouldn’t be here,” Trump said. “I don’t mind being here, but the only reason I’m here is he’s so bad as a president that I’m gonna make America great again.”

Trump went on to criticize Biden’s military policies and said “We’re closer to World War Three than anybody can imagine.”

Biden responded that Trump is a “whiner” and that he “continues to provoke a lie” regarding previous claims of election fraud.