At times the play was as sloppy as the soggy weather conditions. But playing their third game in eight days, the Union did enough to rebound from a difficult midweek defeat.

With Jack McInerney continuing his early-season scoring spree, the Union defeated the Chicago Fire, 1-0, in a Major League Soccer matchup before a sellout crowd of 18,575 at PPL Park in Chester on Saturday.

The Union (5-4-3) have scored successive Saturday wins over the Fire, sandwiched around Wednesday's 4-1 loss to the visiting Los Angeles Galaxy. Chicago is 2-7-1.

Little time was wasted in attacking and breaking the Chicago defense. In the third minute, McInerney scored on a header off a Sebastien Le Toux cross that came from the left side, a few yards outside the box.

In last Saturday's 1-0 win in Chicago, McInerney also scored on a feed from Le Toux.

"It was kind of one of those things where he puts in a good ball, and I was lucky enough to be on the end of both of them," McInerney said.

It was the eighth goal of the season for McInerney, who entered the evening as the league's top goal-scorer. The Union are 5-0-2 when McInerney scores at least one goal.

But right now the striker is thinking about getting some rest after the recent heavy schedule.

"I am a little tired," McInerney said. "But this is the part of the season where you have to work through it."

While the Union were dominant early, Chicago, which has scored just six goals this season, was active offensively.

In the 18th minute, Union keeper Zac MacMath made his best save of the half. After Chicago's Patrick Nyarko turned Amobi Okugo around and fired from a few yards inside the box at the far post, MacMath got a hand on it to steer it wide.

"It came off quick and kind of unexpected, but those are saves I have to make," McMath said.

Union central defender Jeff Parke missed his third straight game with a hamstring injury and once again was replaced by Bakary Soumare, who helped the team record its third shutout.

In the 63d minute, Chicago's Wells Thompson earned his second yellow card of the game to get an automatic ejection.

Contact Marc Narducci at mnarducci@phillynews.com. Follow on Twitter @sjnard.