Sara D. Davis/Getty Images
It's the Republican nominee's largest lead in the poll since mid-July.
In the poll that also includes Libertarian nominee Gary Johnson and Green Party nominee Jill Stein, Trump holds a 44% to 39% advantage over Clinton.
It's an improvement from his 2-point lead in the four-way poll last week, and a much larger improvement from his 4-point deficit in early September.
The poll surveyed 1,000 likely voters between September 20 and 21. It has a margin of error of 3 percentage points.
Just Wednesday, the NBC News/Wall Street Journal poll found Clinton, the Democratic nominee, up 6 points over Trump in the same 4-way race. As of Thursday morning, the former secretary of state held a 1.1-point lead over Trump in the RealClearPolitics polling average.