It was a mixed bag of results for East Contra Costa's council races as two cities saw large changes to their leadership while the other two remained much the same.

Tuesday's election changed the makeup of Oakley and Antioch city councils, with Wade Harper named Antioch's new mayor and newcomers Doug Hardcastle and Diane Burgis elected to vacant Oakley seats.

It also appears that Monica Wilson has won a vacant seat in the Antioch council race, as current Mayor Jim Davis, who opted against a mayoral run this time out, is trailing by less than 1 percent with some mail-in ballots still uncounted as of Wednesday.

Harper, Antioch's Mayor Pro Tem, amassed 40.9 percent of the vote with all of the precincts reporting.

The 24-year police lieutenant, who works in Tracy, said Wednesday he was "humbled" by the community's support.

"I feel really good that I'm going to be able to help develop (the council) as a team, and we will work to address the issues in the city," Harper said.

Harper, who will be Antioch's first African-American mayor, said he is preparing for the role by assessing some of the concerns he heard on the campaign trail, creating a self-management strategy and gathering advice from others.

"It's time to get to work in moving this city forward," he said.

Incumbent Mary Rocha, the lone Antioch council member seeking re-election, won a second term.

In Oakley, Hardcastle led the six candidates with 21.9 percent of the vote, while Burgis has 20 percent. Incumbent Kevin Romick also won a seat with 17 percent of the vote.

"I really didn't know what to expect because if you have any kind of savvy as far as politics, you know people around you are going to tell you how great you're doing," said Burgis, the executive director of a local nonprofit environmental group.

However, Brentwood's and Pittsburg's city councils will remain much the same. The only new face in those two cities is Brentwood's Gene Clare winning the seat of incumbent Bob Brockman.

"I ran one heck of a campaign, and I thank all of my supporters. I ran hard for you and I will run harder as your City Council person," Clare said. "I promise to reward that trust by being an excellent City Council person."

Bob Taylor was again elected mayor in Brentwood by almost a 2-to-1 margin. Erick Stonebarger was re-elected to the other council seat.

Incumbents Ben Johnson and Will Casey won re-election bids in Pittsburg, defeating two challengers.

"My obvious priority is to deal with the difficult financial times we are having not just in Pittsburg but in all of the cities," Casey said. "It's not so much me doing it, it's the five of us on the council."

Staff writers Rowena Coetsee, Paula King and Eve Mitchell contributed to this story.