It may have escaped national viewers of Mayor Bill de Blasio’s performance in Wed­nesday’s debate, but New Yorkers couldn’t help but notice the same old responsibility-dodging, false-credit-grabbing scam artist.

Hecklers disrupted his opening remarks with chants of “Fire Pantaleo!” The mayor later blamed the Obama and Trump Justice Departments for the delay in city action on the case and complained that they hadn’t indicted the cop on civil-rights charges.

Finally, he promised “justice” within “the next 30 days.” But then his campaign spokesperson insisted that the decision rests entirely with Police Commissioner James O’Neill.

On the issue of poisoning from lead paint in public housing, he pointed to decades of federal “disinvestment” — skipping right by his administration’s failures to do federally required inspections and remediation, and his officials’ lies about that non-compliance.

His rivals and the CNN questioners didn’t bother to mention the federal charges against NYCHA, nor the court-ordered monitor now overseeing the agency.

Meanwhile, the city Department of Education quietly posted info revealing that more than 900 city classrooms for young children have tested positive for lead. And the DOE only started that investigation after a WNYC exposé revealed the problem.

Fordham University prof Christine Greer snarked, “Who would be interested in his campaign beyond those doing business with New York City?” Ouch: His campaign, in fact, relies heavily on such donors.

Meanwhile, Gov. Andrew Cuomo aide Melissa DeRosa ripped de Blasio’s claim that he raised the minimum wage to $15 — noting that he had nothing to do with the statewide hike, and passed a city hike only after the statewide one for fast-food workers and others in Rochester, Buffalo and Syracuse.

A bonus humiliation: State records show that the guy championing a “Workers’ Bill of Rights” was just fined for violating worker rights in his 2017 re-election campaign, flaunting compensation, disability and paid-family-leave laws.

No one in Detroit called him out on any of this because he’s at the bottom of pack, and impossibly far from qualifying for the next debate in September: Swatting him down isn’t worth the bother.