Ralph Hernandez, once Superintendent James A. Williams’ harshest critic on the Buffalo Board of Education, switched camps Wednesday and was elected board president with the support of four staunch supporters of Williams.

Hernandez defeated Lou Petrucci, 5-4, dashing the hopes of Petrucci’s camp — which is far more critical and questioning of Williams — that they would gain control of the deeply divided board.

“Is this a victory for James Williams?” Petrucci said moments after the vote. “Of course it is.”

Catherine Nugent Panepinto, the board’s North District representative, said Hernandez switched allegiances to put together five votes.

“I think he’s an opportunist and did what he had to do to be president,” Panepinto said. “I think Ralph philosophically agrees with the people who voted for Lou.”

Hernandez brushed off the opportunist charge.

“She can call me anything she wants,” he said. “I felt I had earned the right to be president. I was campaigning to be president. Where do you go? You go where the votes are. That’s common sense. It has nothing to do with being an opportunist.”

In addition to his own vote, Hernandez had the support of Christopher Jacobs, Florence Johnson, Vivian Evans and Mary Ruth Kapsiak, the outgoing president.

Petrucci voted against Hernandez, and so did Panepinto, Pamela Perry-Cahill and John Licata, who won a board seat in last May’s election and was sworn in prior to the vote for the presidency.

Petrucci said Kapsiak proved to be the swing vote, committing to Hernandez shortly before Wednesday’s meeting.

By identical votes, Jacobs was elected vice president of student achievement and Kapsiak was chosen as vice president of executive affairs.

Licata ousted Catherine Collins — a staunch Williams supporter — from an at-large seat last May. It seemed likely at the time that would switch the balance of power on the board, which would make it difficult for Williams to advance his initiatives or even keep his job. Instead, a pro-Williams majority was kept intact by Hernandez’s switch.

Hernandez was the only board member to vote against hiring Williams in 2005, and clashed with him repeatedly since then.

“Dr. Williams has, in my opinion, mellowed out a little bit,” Hernandez said Wednesday. “He’s very complimentary of the front line people,” including teachers and staff.

Hernandez also cited recent gains in elementary and middle school test scores and in the school system’s graduation rate.

“The district as a whole has been improving,” he said. “We have a long way to go, but we can honestly say we’re making progress.”

Williams said he and Hernandez got off to a rocky start, but patched up their differences in the last several years.

“Ralph’s a good person, loyal and honest,” he said. “I’m looking forward to working with him, and I predict it’s going to be a great year.”

Williams explained the previous clashes this way: “He didn’t know me. I didn’t know him.”