By most accounts, Republican nominee Donald Trump's performance in the third and final presidential debate this week was a failure. But there's one bright prospect for the GOP campaign. According to one poll, about six in ten undecided or third-party voters surveyed just after the event said they would vote for him over his Democratic opponent Hillary Clinton. 

The post-debate YouGov poll found Clinton won the debate handily, 49 percent to 39 percent, with another 12 percent were unsure who won. But among the 1,503 respondents, all of whom watched the third debate, those who were undecided or supported a third-party candidate mostly backed Trump.

YouGov asked respondents who were undecided or voting third-party, "If you had to choose between Hillary Clinton and Donald Trump, who would you choose?" Sixty-one percent chose Trump, while 39 percent said they would support Clinton. Still, the survey found Clinton led Trump 47 percent to 43 percent among respondents overall and undecided/third-party voters composed just 9 percent of the voters in the poll.

Some surveys have suggested Trump actually struggles among undecided voters, including the latest from the Wall Street Journal/NBC News. About 8 percent of the electorate either supported a third-party candidate or was undecided. That 8 percent also tended to want a GOP-controlled Congress, "suggesting they lean Republican but can’t abide" Trump, the survey found.

More post-debate polls have shown non-promising results for the GOP nominee. A Morning Consult/Politico survey released Friday found 43 percent of registered voters thought Clinton won, while just 26 percent said Trump. The same survey found Clinton held a 6-point lead over the GOP nominee, but 15 percent remained undecided. 

The biggest moment of the debate also proved to be a negative one for Trump, who earned headlines for refusing to commit to accepting the results of the 2016 election. "What I'm saying now is I will tell you at the time. I will keep you in suspense, OK?" Trump said during the debate. 

Nearly 70 percent of respondents in the Politico/Morning Consult survey felt nominees should accept the results of the election.