Rep. Jason Altmire led Rep. Mark Critz by a mere 4 points in a test of Tuesday’s Democratic primary matchup, according to a poll released today.

The Tribune-Review/WPXI-TV poll showed Altmire ahead of Critz 43 percent to 39 percent in the finals days of their increasingly competitive contest.

The two Democrats are facing off in southwestern Pennsylvania’s 12 district after GOP-led redistricting combined their current territory.

This new survey shows Critz has closed the gap significantly in the race compared to earlier polls. In mid-March, Altmire released an internal poll that showed him with a whopping 24-point lead over Critz. Ten days later, Critz released his own internal poll that showed him trailing Altmire by just 7 points.

Susquehanna Polling and Research conducted the survey of 400 likely Democratic primary voters from April 13-15. The poll had a margin of error of 4.9 points.

The likely GOP nominee is attorney Keith Rothfus, who unsuccessfully ran against Altmire last cycle. Roll Call rates the general election race as a Tossup.