Armed with new test scores showing a strong performance by her 15,000 students, the head of the Success Academy network of charter schools takes a victory lap - and seizes an opportunity to bash her long-time sparring partner Mayor de Blasio. NY1's education reporter Lindsey Christ filed the following report: 

The city's leading charter school operator is back on the offensive, barely a week after she made two humbling apologies -- one for ties to the Trump administration, the other for comments by her board chairman. 

Eva Moskowitz gathered reporters Thursday to crow about the performance of her students in the most recent round of statewide testing -- and berate Mayor de Blasio for celebrating a more modest uptick in public school scores. 

"What is going on in a city that is spending $31 billion a year and accepting massive failure?" said Moskowitz, the founder and CEO of the Success Academy charter schools.. 

"I'm outraged by the educational racisim engendered by the system. I'm also frustrated by the Mayor's response, and I know the journalists it the room are gonna think it's personal. It's not personal. The mayor's a good man, it's hard to run the city of New York, but his reaction to the scores is not appropriate," she said.

Scores out Tuesday show that 95 percent of students of color at her Success Academy schools passed the math exam, compared to 24 percent in city public schools. And 83 percent of students of color at Success passed the English test; only 29 percent in public schools did. 

"The mayor is out celebrating ... a 60 percent failure rate is not worthy of a celebration. It is a moment to stand up and say, 'What is going on and how did this injustice occur?' "

De Blasio has never embraced charter schools or Moskowitz. Two weeks ago, he demanded her board chairman, hedge fund billionaire Dan Loeb, resign for saying a black state senator has done "more damage to people of color than" the Ku Klux Klan. The mayor's office dismissed Moskowitz's new attack. 

"We have implemented real reforms to help close the achievement gap," a spokeswoman said. "This is nothing more than a stunt designed to distract from the deeply offensive and disqualifying comments made by Success Academy's leading financier."

Moskowitz often seems to court controversy and she has been feuding with de Blasio for years, dating back to when they were both on the City Council. 

And with de Blasio favored to win re-election, their back and forth is likely far from over..