The 84-year-old performer did not require hospitalization and Berry's friend, Joe Edwards, said he appeared to have fully recovered.
"I think it was just exhaustion," Edwards said, noting that Berry played two shows in New York on New Year's Eve, then flew to Chicago where he played at the Congress Theater on Saturday night.
"I think by the time the concert in Chicago got near the end he just got tired," he said.
Berry's agent, Dick Alen, said in an e-mail to The Associated Press that the singer "feels tired but good."
Edwards said Berry returned to his home in Wentzville, Mo., on Sunday afternoon, and that he is feeling well enough to prepare for a Jan. 19 concert at Blueberry Hill in University City, Mo. Berry has performed monthly concerts at the popular bar and restaurant that Edwards owns since 1996.
"He's in great shape," Edwards said of the singer of early rock classics such as "Johnny B. Goode," "Sweet Little Sixteen" and "Roll Over Beethoven."
"He's very healthy. He doesn't smoke or drink. He cuts his own grass," Edwards said.
A man who attended the Chicago concert said Berry gave an erratic, out-of-tune performance before he was helped offstage. After a few minutes he came back, thanked the crowd and gave a brief description of what happened, then did a few steps of his famous "duck walk" before calling it a night.
Berry grew up in St. Louis. In December 2008, the modest one-story red-brick home where he lived for eight years in the 1950s, as his fame began to soar, was added to the National Register of Historic Places.
Edwards has called Berry St. Louis' greatest worldwide ambassador, noting that his music has influenced acts from the Beatles to Bruce Springsteen.
Berry still sings, plays guitar and performs the duck walk during his performances, despite his advancing years. Edwards said the shows at Blueberry Hill - named the Duck Room for Berry - sell out every month with visitors coming from around the world to see him perform.
When Berry's friend and collaborator Johnnie Johnson - the inspiration for "Johnny B. Goode" - died in 2005, Berry told reporters he would miss his friend but wasn't melancholy.
"My turn is coming very soon," Berry said at the time. "Would you shed a tear for Chuck? I hope not, because I don't see why one should weep when something inevitable must come."