Tommy La Stella homered starting the third, Dexter Fowler walked, Jorge Soler singled and Rizzo sent an 0-2 pitch from Lohse over the left-field fence.
Fowler hit a two-run homer in the fourth off Lohse, who allowed seven runs, eight hits and four walks in four innings. Jorge Soler hit a two-run homer off Will Smith in the fifth.
Hammel gave up six hits, struck out five and walked none. The right-hander, who will pitch either the Cubs' second or third game, pronounced himself happy with the spring.
"I got the pitch counts up where they needed to be. I still felt really strong in the fifth today. That's pretty much all you can ask for — stay healthy and get ready," Hammel said.
An announced crowd of 13,375 at Sloan Park raised the Cubs' home total to 222,415, a major league spring training record that topped Chicago's total of 213,815 last year.
Fowler went 3 for 3 with four runs scored. Soler, La Stella and Matt Szczur all had two hits apiece.
Brewers: Lohse, who gave up three homers, is scheduled to start the season opener Monday against Colorado. He said he didn't have the feel for his changeup Wednesday but kept trying to work on it.
"It's not an, 'Oh well,'" he said. "It's, 'OK, let's think about what we need to work on for the next start.'"
In the longer view, he said he's healthy and ready to go.
"That's the most important thing. Except for this, I felt like every other outing was really solid," Lohse said. "This start was ugly, but you turn the page. The next one is the one that counts."
Milwaukee manager Ron Roenicke said he likes how Lohse has been pitching. Lohse entered the game with a 1.80 ERA this spring.
"I don't know how to explain today," Roenicke said. "Sometimes, your command just isn't there. Sometimes you're facing a pretty good team. He knows what he needs to do. We feel good with him opening up."
Cubs: Jon Lester is likely to throw about 100 pitches in the season opener Sunday night vs. St. Louis. Also, manager Joe Maddon will soon decide on his fifth starter, choosing between Travis Wood and Edwin Jackson, with the other going to the bullpen.
Brewers: Ryan Braun sat out with a tight hamstring. The team hopes he'll be ready to go Thursday.
"I tried to impress upon these guys to stay ready because the call could come at any moment," Maddon said. "The guy who goes out there and continues to do his job and stays ready gets that call."
Brewers: Matt Garza pitches Thursday against the San Diego Padres in Peoria.
Cubs: Jackson takes the mound Friday against the Arizona Diamondbacks.