PHILADELPHIA — Buoyed by increased support among Republicans in Ohio, Donald Trump has pulled even with Hillary Clinton in a head-to-head match-up in the state, and he is ahead of her in a four-way contest, according to a survey taken in the days after the Republican National Convention in Cleveland.

Mr. Trump and Mrs. Clinton were tied at 45 percent head-to-head in the poll released Monday by the Democratic-leaning firm Public Policy Polling, after Mrs. Clinton had held a 4-point, 44 percent to 40 percent lead, in June.

Mr. Trump’s support among Republicans increased from 66 percent to 82 percent, while Mrs. Clinton’s support among Democrats increased from 76 percent to 84 percent. Mrs. Clinton retained a 1-point lead among independents.

SEE ALSO: Bounce: Donald Trump surges to lead after GOP convention

In a four-way contest, Mr. Trump led Mrs. Clinton by 3 points, 42 percent to 39 percent, with Libertarian Party presidential nominee Gary Johnson at 6 percent and Green Party candidate Jill Stein at 2 percent.

“The Republican convention in Ohio seems to have helped unify GOP voters in the state around Donald Trump,” said Dean Debnam, president of Public Policy Polling. “But it didn’t help him make any in roads with independents or Democrats.”

Other polling has given Mr. Trump a post-convention bump as well. A national CNN/ORC poll released Monday put Mr. Trump up 3 points over Mrs. Clinton, 48 percent to 45 percent — a lead that stretched to 5 points with Mr. Johnson and Ms. Stein in the mix.

But a poll conducted after the GOP convention for WSB-2 in Georgia gave Mr. Trump just about a 2-point lead over Mrs. Clinton in the state, 46 percent to 44 percent, with Mr. Johnson at about 5 percent and Ms. Stein at about 3 percent. Georgia last voted for a Democratic presidential nominee in 1992.

Other polling has shown Mr. Trump running competitively with Mrs. Clinton in traditional battleground states like Ohio, Pennsylvania, and Florida - but also that Mrs. Clinton has a chance to make Mr. Trump play defense in traditionally red states like Arizona.

Mr. Trump spent part of the day Monday campaigning in North Carolina. President Obama narrowly carried the state in 2008 — becoming the first Democratic presidential nominee since 1976 to do so — but lost it in 2012.