May wobbled on many issues apart from Brexit - but still may have reassured voters that she is a solid commander of a nation reeling from a terrorist bombing that killed 22 people last week. Many political observers characterised the television appearance as a draw.
"We have to be prepared to walk out" of Brexit negotiations, May said under rat-a-tat questioning from Channel 4 anchor Jeremy Paxman, repeating a vow she made when she triggered the two-year ticking negotiation clock in March. "No deal is better than a bad deal," she said.
She sidestepped several questions about the scale of unpopular cuts in public funding for nursing care for elderly people and education, saying in one case that "we'll take people's views" on the ultimate figure. Some of her responses about her views on slashing the safety net drew jeers from the audience.
Corbyn eschewed many of the sound bites that characterise this form of politicking, disarming a studio audience with humour and making strides in erasing a public image as a tense far-left campaigner who has trouble connecting with the concerns of working-class voters.
"Do you know what, I had a very nice chat with the Queen," Corbyn said to laughter after being pressed on whether he would abolish the monarchy, a long-held personal belief that is not part of Labour's official platform. "We're not going to do it," he said.
But he stumbled on some of the topics that may be most critical for undecided voters, including his past expressions of support for members of the IRA and his readiness to launch drone strikes against suspected terrorists in the Middle East.
"You can't answer a hypothetical question without all the evidence around," Corbyn said when asked whether he would be willing to launch a strike if British security officials told him they had someone in their crosshairs.
The issue may be especially sticky after last Tuesday's bombing outside a Manchester concert hall, the worst terrorism strike in Britain since 2005.
Since the TV appearances aired on a holiday in Britain, the least committed voters probably will not have watched the full exchange live - which might have given Corbyn an advantage. They were more likely to see highlights during news programmes, amplifying the missteps and muting the overall impact of his performance.
Most opinion polls still differ only on the scale of May's probable victory.
Corbyn has struggled to connect with a broad section of British voters after being made party leader by a hardcore group of left-wing party activists in 2015.