Minka vanBeuzekom celebrates with her daughter, Anya, moments after preliminarily winning election to the City Council in a Tuesday ballot count. (Photo: Marc Levy)

The City Council and School Committee each gained a challenger — losing an incumbent — in a preliminary election count Tuesday.

The new councillor is Minka vanBeuzekom, who is thought to have won 1,011 No. 1 votes out of the 15,393 council ballots cast. Sam Seidel, who has been on the council since 2007, looks to be losing his seat. Election commissioners put his No. 1 votes at 768.

But an equally big story for the night was the reelection of Leland Cheung, who topped 1,974 ballots to become the night’s biggest vote-getter. Cheung will be serving his second term, having squeaked through in 2009 with 756 No. 1 votes. Although throughout the campaign he feared he would join the ranks of first-termers who lost their seat, instead he got the numbers he needed — roughly one-tenth the number of voters — and a 400-vote surplus.

“A remarkable achievement, without question,” politics watcher Robert Winters said during commentary on CCTV with Susana Segat.

Other incumbents who were reelected included Tim Toomey (1,654 votes), David Maher (1,636), Henrietta Davis (1,407), Denise Simmons (1,224), Marjorie Decker (1,092), Craig Kelley (1,075) and Ken Reeves (979).

On the preliminary School Committee votes, of which election commissioners counted 14,939, incumbent Nancy Tauber lost her seat (with 1,463 votes) and challenger Mervan Osborne gained it (with 2,036 votes).

The incumbents that survived were Fred Fantini (2,318 votes), Patty Nolan (2,090), Alice Turkel (2,075), Richard Harding (1,801) and Marc McGovern (1,744).

Challengers that failed to win committee seats included  Joyce Gerber (430 votes), John Holland (379), Bill Forster (321) and Charles Stead (282), while challengers missing out on council seats include Larry Ward (816), Matt Nelson (523 votes), Charles Marquardt (488), Tom Stohlman (336), James Williamson (171), Gary Mello (128), Jamake Pascual (57) and Gregg Moree (54).

Preliminary quota, said election commissioner Polyxane S. Cobb, was 1,540 votes. The count will continue with write-ins, overseas and other stray categories of ballots, she said. In the municipal elections two years ago, 16,073 ballots were cast, leaving this low voter count still far ahead of the 13,721 seen four years ago.

Even coming in less than four hours after polls closed is fast for Cambridge in some election years. “It’s quite a thing, putting on a PR election,” Cobb said, referring to Cambridge’ proportional representation form of voting. The count was done as usual at the Senior Center in Central Square, across from City Hall.