Abdul El-Sayed has won the Democratic nomination for U.S. Senate in Michigan, delivering a major victory to the party’s progressive wing in the battleground state. He narrowly defeated U.S. Rep. Haley Stevens in the primary.

El-Sayed, a former public health official, ran as an insurgent candidate amid frustration among Democrats with the party establishment. His victory places a progressive contender at the center of Michigan’s Senate contest.

El-Sayed will face Republican Mike Rogers in November. The result sets up a closely watched general election for a Senate seat that could carry significance in the battleground state.