Among likely Democratic primary voters in the Keystone State, Clinton has 52% support to Sanders' 39%.
Fueling Clinton's lead is a major gender gap. The former secretary of state holds a 61% to 32% edge among women, compared to Sanders' smaller 50% to 41% advantage with men.
Clinton also outperforms Sanders with voters aged 50 and older, leading that group 57% to 33%, while Sanders' lead with those younger than 50 is just 48% to 46%.
Both these trends mirror voting results.
Similar to New York, where Clinton notched a dominant victory on Tuesday, the former secretary of state has an important advantage in Pennsylvania: It's a closed primary, which means only registered Democrats can participate. It's a rule that bars Sanders from bringing a crush of independents to the polls on his behalf, as he has in many of the states he's won.
"After her win in New York this week, these numbers in nearby Pennsylvania suggest that the entire northeast is looking pretty good for the Clinton campaign," Patrick Murray, director of the Monmouth University Polling Institute, said in a statement accompanying the poll's release.
Pennsylvania also has a hotly contested Democratic Senate primary, with former Rep. Joe Sestak facing off against Katie McGinty, a former state official who is backed by national Democrats. The two are tied at 39% apiece, the poll shows.
The poll surveyed 302 likely Democratic voters between April 17-19 -- which means all the results came in before Clinton's New York win -- and has a margin of error of plus or minus 5.6 percentage points.