LOGAN SQUARE — Incumbent Milly Santiago is headed to a runoff election in the 31st Ward.

With 97.6 percent of the precincts reporting, Santiago, who won the seat in 2015, was leading with 40.5 percent of the vote to about 33 percent for Felix Cardona Jr., according to unofficial election results provided by the Chicago Board of Elections.

A candidate needs more than 50 percent of the vote to avoid a runoff against the second-place finisher.

Santiago narrowly won the seat in 2015. Before Santiago, the ward had the same boss for nearly 25 years: Ald. Ray Suarez. The Vietnam War veteran was first elected to lead the Northwest Side ward in 1991.

Santiago, a former TV reporter, made headlines in 2016 when she complained about a new rule that bans aldermen from taking advantage of an offer from the Chicago Cubs to buy postseason tickets at face value. She later apologized.

First-time candidate Felix Cardona Jr. worked for the Cook County Board of Review and then the Cook County Assessor’s Office. His father served as vice president of the Puerto Rican Parade Committee in the 1990s.

A third challenger, Colin Bird-Martinez, secured 26 percent of the vote with 97 of the precincts reporting.

The 31st Ward includes parts of Hermosa, Belmont Cragin, Portage Park and Logan Square.