Democrat Senator Elizabeth Warren and her Republican challenger, Massachusetts state Representative Geoff Diehl, clashed on everything from tax cuts to immigration to Warren's decision to release a DNA test during their first debate Friday.

The meeting was combative at times, with the candidates challenging each other and sometimes talking over one another.

Diehl faulted Warren during the televised debate for opposing the Republican-led tax bill, which he said benefited local taxpayers and businesses.

'Eighty percent of Massachusetts residents are getting a tax cut, lower taxes federally, because of that tax reform,' Diehl said. 'That's why we're seeing, now, businesses reinvesting.'

Massachusetts Senate candidates Sen. Elizabeth Warren and her opponent State Rep. Geoff Diehl shake hands before a debate in Boston on Friday

Warren said the bill works for billionaires and corporations - and not enough for ordinary taxpayers - while expanding the deficit, which she said is giving Republicans a reason to target cuts to Social Security and Medicare.

'This is the basic Republican scam and that is cut taxes for those at the top and make everyone else pay for it,' she said. 'This economy is working better and better and better for a thinner and thinner and thinner slice at the top.'

Warren, a possible 2020 presidential candidate running for a second six-year Senate term, defended her decision to release DNA test results this week that provide some evidence a Native American is in her bloodline.

Warren released the tests in part to counter President Donald Trump, who has repeatedly criticized Warren's claims of Native American heritage, calling her 'Pocahontas.'

Warren also said she released the tests for the same reason she put 10 years of her tax returns online and released hiring records from her career as a law professor.

'The whole notion of confidence in government has really gone to a low point and so for me, what I've done is I've just tried to put it all out there,' she said. 'I am an open book.'

Warren defended her release of a DNA test showing minute Native ancestry. Diehl did not call her 'Pocahontas' but accused her of posing as a minority to benefit from affirmative action

Warren said she's not claiming to be a citizen of any tribal nation.

Diehl, who co-chaired President Donald Trump's 2016 Massachusetts presidential campaign, said he didn't care about Warren's heritage, but suggested Warren may have benefited from listing her Native American heritage in a national directory.

'It seems that maybe that was inappropriate to list yourself,' Diehl said, suggesting Warren may have ended up 'taking a minority hire position away from somebody else.'

Warren said that 'nothing in my background ever made any difference in my hiring.' She criticized Diehl for not releasing his tax returns.

On immigration, Diehl said Warren supports eliminating U.S. Immigration and Customs Enforcement. Warren said she backs a comprehensive approach to immigration and border security.

Warren repeatedly tried to tie Diehl to Trump, who remains unpopular in Massachusetts.

'Let's talk about - if we're going to talk about character - what it means to have Donald Trump's back,' she said. 'It means standing by Donald Trump when he calls white supremacists in Charlottesville 'fine people.''

Sen. Elizabeth Warren greets supporters before a debate with her Republican opponent Geoff Diehl in Boston on Friday

Diehl didn't back down from his support of Trump, but said he wouldn't vote in lockstep with Trump or Senate Republicans.

'I am not a Mitch McConnell Republican, I'm a Massachusetts Republican,' he said, referring to the GOP Senate majority leader.

Diehl said Warren has taken her eye off her day job representing Massachusetts by exploring a White House run. Warren has said she'll take 'a hard look' at a 2020 run after the midterm elections.

'You are running for president. Everybody knows,' Diehl said. 'It's not a secret at all.'

The two were also asked about Saudi journalist Jamal Khashoggi, who Saudi officials claimed was killed in a 'fistfight' in the Saudi Consulate in Istanbul. Turkish officials have said an 'assassination squad' from the kingdom flew in and laid in wait for Khashoggi.

David Duffy shows support for Massachusetts Republican Senate candidate Geoff Diehl before a debate with incumbent Democrat Sen. Elizabeth Warren in Boston

Warren said Khashoggi's fate 'was an attack on democracy all around the world.'

'The response should come not just from the United States but should come all around the world, otherwise we empower dictators to kill journalists who ask hard questions,' Warren said. 'Do we need a strong response on Saudi Arabia? Absolutely. And Donald Trump is showing he is not capable.'

Diehl said the U.S. needs to protect press freedoms, but called Saudi Arabia a strong ally.

'We need to continue to have a relationship,' he said, pointing to companies in Massachusetts that do business in the kingdom. He also credited Saudi Arabia with helping keep terrorism in check 'in their own backyard.'

Independent candidate Shiva Ayyadurai is also on the ballot, and has protested to be allowed onto the debate stage. On Friday he sat in the road as the car carrying Warren approached the debate, which was broadcast on WSBK-TV.

There are two more scheduled debates before Election Day.