Mayor Zohran Mamdani is doing the right thing in fighting the City Council’s push to award teaching bonuses outside the collective-bargaining process. 

The mayor is suing to stop the $10,000 grants to special-education paraprofessionals because they’d set a disastrous precedent.

City Council Speaker Julie Menin argues the move would save the city money on support it’s legally required to give many special-needs kids, but it’s an obvious long-term loser — and open invitation for every public-employee union to get lawmakers to award them gifts so to win union backing at the next election.

We fear that last is why the council voted unanimously for the payment last month, a veto-proof majority that left the mayor no choice but to head to court, arguing that the move violates state labor law.

Lawmakers can’t reduce union-worker pay without collective bargaining; letting the council add pay would badly undermine a core mayoral authority.

Kudos to Mamdani for eating his campaign promise to support the bonus bill; it’s a sign of good sense that he looked more carefully and thought better.

United Federation of Teachers chief Michael Mulgrew is furious, naturally; tough.

The UFT inevitably gets almost everything it asks for, anyway.

Mamdani’s courage here might even signal a willingness to stand firm in the coming round of contract talks with every city union; he doesn’t owe his office to them, after all.

We’ll cross our fingers and hope for yet another pleasant surprise.