The Italians were knocked out of the competition and Puerto Rico survived in the double-elimination portion of the tournament.
Puerto Rico will return on Friday to play for a spot in the semifinals against the loser of Thursday's game between the United States and the Dominican Republic. The winner of Thursday's contest will join Japan and the Netherlands in the semifinals, which will be held next week in San Francisco.
Italy held a 3-1 lead heading into the eighth, but Carlos Beltran drew a walk to open the inning and moved to third on a single by Yadier Molina. Mike Aviles delivered the first run of the inning by grounding to second with Molina being wiped out in a force play.
Alex Rios followed with a single that sent Aviles to third, from where he scored the tying run on a sacrifice fly by Luis Figueroa.
Rios moved to second on Figueroa's fly ball and sped home when a grounder by Gonzalez deflected off the glove of third baseman Alex Liddi.
The win went to Hiram Burgos, who worked 3 2/3 scoreless innings of relief. Fernando Cabrera came on with two away and one on in the ninth and struck out Liddi to end the game.