The fan was transported to Froedtert Hospital and is now recovering. She is in satisfactory condition, according to an Associated Press report.
Play was halted for nine minutes as stadium personnel and EMTs attended to the fan who was seated approximately seven rows above the Brewers' dugout on the first-base side.
The fan, whose forehead appeared to be covered with a towel, eventually walked gingerly with the assistance of EMTs to the end of the aisle. She was placed in a chair and taken away from the field for further treatment and evaluation.
Braves shortstop Andrelton Simmons, who was on first base at the time, was among the players who displayed concern while play was halted.
"When a ball is hit that hard into a crowded area, chances are somebody is going to get hit," Braves Simmons said. "You hope nobody gets hit and if somebody gets hit, you hope it's in the arm or only so much damage is done. But when somebody gets hit in the face, it's almost always going to end up bad."
Simmons expressed hope that Major League teams will begin extending the protective nets down the baselines to shield fans from becoming unfortunate victims of these kinds of events.
"Sometimes you wish the net was bigger to at least cover the people that don't have time to react," Simmons said. "I wouldn't sit that close without a net."
Mark Bowman is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.