Mayor John DeStefano Jr. coasted to re-election in Tuesday’s primary, but many of the aldermanic candidates he supported in key wards learned that the mayor’s coattails don’t guarantee victory.

While DeStefano-backed candidates lost in several key races, DeStefano allies won in eight of the 12 contested primaries.

In Ward 22, which includes Dixwell and Morse and Ezra Stiles colleges, one-time alderman Mae Ola Riddick won back her seat from her successor, Grace Gibbs. Gibbs had been supported by Looney while Riddick had DeStefano’s backing. The margin of victory was four votes.

In the highly contentious Fair Haven race, considered by campaign workers as “ground zero” in the mayoral race, all three incumbent aldermen and Looney supporters won — even as DeStefano carried two of the three wards.

Police officers and campaign workers came prepared for an intense day at the polls in the three Fair Haven wards, 14, 15 and 16, where complaints of stolen campaign signs and physical intimidation have contributed to a less-than-cordial race.

But on a day in which terrorist attacks on the nation’s financial and military headquarters brought most attention away from local ward races, turnout was slow and candidates carried a new perspective on the race.

“This unfortunate national situation is much more important than the New Haven race,” said Alderwoman Robin Kroogman, who defeated challenger Kevin Walton by 86 votes. “It makes the local election seem so much smaller.”

Walton, who worried the national events would keep many of his supporters from coming to the polls, spent part of his morning on the phone, trying to reach two family members who worked at the World Trade Center, which collapsed early Tuesday after two planes crashed into it.

But tempers did rise several times in the morning, including a yelling match between Walton and a Looney volunteer just after the polls opened at 6 a.m. Later in the day, the camps again clashed as Kroogman supporters accused Walton of accosting an elderly resident and taking his pro-Looney voting guide.

Walton denied the accusations and the voter, 80-year-old Alphonse Mele, could not recall the incident.

But the ensuing confusion was enough to lead to a brief yelling match, in which Kroogman volunteer Julie Delucia accused the DeStefano camp of intimidating Mele, and Teresa Vera, a DeStefano supporter, accused Delucia of violating election regulations.

“We know who you voted for,” Vera shouted at the confused Mele. “It’s a clean race.”

In Ward 16, where tensions have also run high in the past few weeks, the election was carried off with a little less excitement.

With a police substation 100 feet away, DeStefano-backed Edwin Negroni, Looney-supported Raul Avila, the incumbent, and Catalino Acevedo greeted voters while avoiding each other. Negroni made several complaints about Avila to police officers, claiming Avila violated a new election law barring candidates from entering the polling location more than once.

In Ward 15, which includes part of Fair Haven, Looney-supported candidate Kevin Diaz defeated DeStefano-backed Daisy Montanez Couverthier by 86 votes.

Another Looney supporter, Ward 8 alderman Vincent Mauro Jr., defeated challenger Michael Howell by 46 votes.

Near Yale, however, DeStefano supporters fared better.

In Dwight’s Ward 2, incumbent Alderman Linda Townsend-Maier defeated challenger David Watts DIV ’03 in a race that drew an unusually high turnout for a chronically low-voting neighborhood.

Nearly one-quarter of registered ward voters made their way to the Dixwell Fire Station, where the two candidates camped 10 feet apart and competed to barrage voters with literature.

Townsend-Maier, who was appointed a week ago to replace former Alderman Jelani Lawson, said she was pleased with her victory in a challenging race.

“I’m extremely excited,” she said shortly after hearing the results. “I didn’t know what to expect.”

Watts, who had plugged himself as “David” to Townsend-Maier’s City Hall-supported Goliath, expressed disappointment at the outcome.

“At the end of the day, machine politics tends to win out,” Watts said, alluding Townsend-Maier’s support by the mayor. He was defeated but not completely disheartened.

“I think along the line I’ll be involved in politics again,” he said.

As he left the polling station, Watts promised Green Party candidate Joyce Chen ’01 to support her in the general election.

One Looney-supported incumbent, Anthony Dawson of Ward 3, lost his race to DeStefano-backed Juan A. Candelaria.

Other incumbents who won included Portia Jenkins in Ward 30, and DeStefano-backed candidates Lindy Gold in Ward 26, Bruce McClenning in Ward 28 and Charles Blango in Ward 20.