Mayor Bill de Blasio took another victory lap touting his creation of universal pre-kindergarten on the first day of school Wednesday. NY1's Lindsey Christ filed the following report.

It was the first day of school for 1.1 million students, which, for Mayor Bill de Blasio, meant a day full of reading story books, sitting in tiny chairs and playing with Play-Doh.

For the second year in a row, the mayor spent the day in classrooms in all five boroughs. He was celebrating the universal pre-K program he promised as a candidate, which is now finally in place. There are 65,000 4-year-olds enrolled and a place for every child whose parents want one, to the tune of $500 million a year.

"We have more kids today in full-day pre-K than there are in the entire school system of Boston or Seattle," de Blasio said.

Officials had initially hoped to enroll more than 70,000 students in pre-K, and throughout the city Tuesday, the mayor emphasized that it's not too late for parents who want to sign up.

"There are some communities, and central Brooklyn is an example, where we're still not seeing the kind of enrollment that we should," de Blasio said.

Schools chancellor Carmen Fariña, celebrating her 50th year working in city schools, began the day on Staten Island with the mayor and then continued on her own five-borough school tour.

She ended at Renaissance School of the Arts in Harlem, one of 94 so-called renewal schools. These are the struggling schools at risk of state takeover that the de Blasio administration is trying to fix by extending the school day and adding extra social services.

"These are all successful schools, schools on the march, schools that are trying everything," Fariña said.

This will be a critical year for the mayor when it comes to education. Supporters expect, and critics demand, results from the pre-K program and the school reform policies. And over the course of the school year, de Blasio must once again prove to Governor Andrew Cuomo and lawmakers in Albany that they should renew mayoral control of the school system, which, if they don't act, will expire in June.