Two council incumbents, Leamon Pierce and Linda Bennett, are in runoffs, as are newcomers Peter Murphy and J.T. McDaniel in District 9.
City Council Chairwoman Linda Bennett, 55, is headed for an April 14 runoff with opponent Deborah Scott, 55.
Ms. Bennett said she'll try to pick up more votes in the Lookout Valley area.
"I expect to be working very hard for the next few weeks," she said.
Ms. Scott said she plans to "emphasize the same message we've had from the beginning" - fiscal responsibility, infrastructure and crime issues.
The two candidates will battle it out to represent District 1, which covers Lookout Valley, Moccasin Bend and part of North Chattanooga.
Ms. Bennett, who has served one term, has been the council's chairwoman since last April.
Candidate Joe Graham came in third.
Longtime District 8 City Councilman Leamon Pierce faced a stiff challenge Tuesday. Without provisional ballots, which will be counted this week, Mr. Pierce lacked the 50 percent-plus-one-vote totals needed to stave off an April 14 runoff with political newcomer Andraé McGary.
"It's not the most desirable outcome, but this is what we've got," said Mr. Pierce, 67. "We'll slow down for a week or two, and pick back up after meeting with my committee and seeing what direction we're going in."
Over at Mr. McGary's campaign party at the Terminal restaurant, he was cutting a congratulatory chocolate cake.
"We knew that we either had to win to or get into a runoff to move forward," said Mr. McGary, 29. "People knew that it was time for a change."
A third challenger, Dennis Clark, 25, came in a distant third.
A five-candidate race for the District 9 seat will head to a runoff.
J.T. McDaniel and Peter B. Murphy were the two highest vote getters, but neither nabbed the 50 percent plus one vote needed to avoid an April 14 runoff.
"We were hopeful that we would get a clear majority, but we are grateful to the voters that we received enough votes sufficient to continue on until April," said Mr. Murphy, who received the most votes Tuesday.
Mr. McDaniel said his platform, which focused on reducing crime, resonated with voters.
"Crime is on the increase, and voters agreed with my platform," he said.
The seat is vacant after incumbent Debbie Gaines decided not to seek a second term on the council.
Vote totals for one precinct in each race were not available Tuesday night. That precinct is reserved for provisional ballots, election officials said.
Staff writers Matt Wilson, Cliff Hightower and Adam Crisp compiled this report.