It was the fourth 10-run first in club history and the first since June 2, 2002, against the Expos. The others were on Aug. 5, 1975, against the Cubs, and on Aug. 13, 1948, against the New York Giants.
Shane Victorino -- in the running for the 2009 All-Star Game Sprint Final Vote -- launched Cueto's ninth pitch of the night over the right-field wall for a two-run homer.
And the inning was just beginning.
Left fielder Greg Dobbs (two-run shot) and second baseman Chase Utley (three-run blast) would also homer, starter Cole Hammels helped his own cause with a two-run double and every Phillies player except Ryan Howard reached base. Philadelphia scored eight of its 10 runs in th frame with two outs.
"It was one of those nights where everything we hit was falling, but we also hit balls hard," Phillies manager Charlie Manuel said. "It gives our hitters a lot of morale, a lot of confidence, makes them feel good about their performance and themselves."
Said Victorino, who finished 4-for-5 with five runs scored and four RBIs: "We were able to score 10 runs in the first against a guy like Cueto, so that's big."
Cueto had been Cincinnati's best pitcher this season but lasted just two-thirds of an inning, the shortest outing of his career. He allowed nine runs, all earned, on five hits three walks and one hit batsman, watching his ERA jump from 2.69 to 3.45.
Hamels was the recipient of the early runs and he cruised, allowing just three hits and no walks over seven innings. He needed just 92 pitches.
"The runs just definitely helped," Hamels said. "It makes it a lot easier to go out there and not really worry or put too much pressure on yourself when you have 10 runs in the first inning. Most teams barely score 10 runs total at all, and we score that in the first inning -- and then some."
David Gurian-Peck is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.