And you'd always heard it was Phoenix that rose from the ashes!
"It's certainly terrific for the city of Philadelphia, a tremendous boost to our civic pride and a reaffirmation of many of the things we're doing here in the city," Mayor Nutter said. "We could not be more thrilled."
In Phoenix, clearly stunned local officials fell back on every scoundrel's last refuges: their perfect weather, and a better sense of humor.
"In homes and offices all around Phoenix, we gathered together holding our collective breath this afternoon, waiting to learn whether we'd still be ahead of Philly in the latest population stats," said Janey Pearl, senior assistant to Phoenix Mayor Phil Gordon.
"Alas, we fell short. The good news is, we consoled ourselves with yet another perfect, cloudless 80-degree day here in the Valley of the Sun. Enjoy those thunderstorms and high of 56, Philadelphians."
Fans of Philadelphia had been bemoaning bad news on the population front long before we mourned the first of the Phillies' record 10,232 losses. Ironically, the city was cheated in the first Census in 1790, which reported that New York was larger than the Cradle of Liberty, but only because Northern Liberties and Southwark (South Philly) were counted separately.
Since then, we've been passed by Chicago (1890) during the Industrial Revolution and Los Angeles (1960) and Houston (1990) with the invention of the air conditioner - but now we've drawn a line in the desert.
How did this happen? It certainly helped that Philadelphia - after decades of flight to the suburbs - stopped shrinking in the 2000s thanks to new arrivals from everywhere from Mexico to Cambodia, and even a few from the exotic land known as Tribeca.
But at least one population-watcher in Arizona said that there's evidence that Phoenix might have passed Philadelphia for a brief time in the mid-2000s but that the city and the surrounding Valley of the Sun may have actually lost people since then.
Tom Rex, an economist at Arizona State University who studies population trends, said that Arizona has been hammered by the collapse of the Sunbelt housing bubble that had inflated to epic levels midway through the decade, and by its hostile climate toward Hispanic immigration.
Rex said that the 2008 enactment of a law seeking to crack down on companies hiring illegal immigrants caused thousands of Latinos to flee. Under that law, and with political support for an immigration crackdown, Phoenix-area Sheriff Joe Arpaio has conducted a series of high-profile raids going after undocumented Hispanics.
Staff writer Bob Warner contributed to this report.