From among 14,000 participants, Portilla was selected as the winner of a contest on the Giants' website. He was chosen at random for a weekend trip to New York City to see his Giants play a series against the Mets and to visit the MLB Fan Cave.
"Dream is really the best and only way to describe it," said Portilla, admittedly still in a daze from his weekend in the Big Apple. "I knew what it was, but being there and getting to do so many cool things was unbelievable. I couldn't have even imagined how awesome or how cool it was going to be."
Portilla was given free round-trip airfare for himself and a friend (he took Rivas), a room in the team hotel and $300 spending money, which he used to see a Broadway play on Saturday.
What was his response when he found out he was headed across the country to watch the Giants play at Citi Field?
"You probably can't print my initial reaction," Portilla said. "Just total shock."
On Friday night, Portilla and Rivas watched the game from the sixth row behind the first-base dugout. They got to see the Giants stave off the Mets, 4-3, in a 10-inning thriller that came down to a Lucas Duda fly ball to end the game with runners on second and third.
Then, on Saturday, they took in the afternoon game from the Fan Cave, where they met the Cave Dwellers, most notably fellow Giants fan Ashley Chavez. Afterward, Portilla and Rivas saw "Once," a Broadway musical, and then spent some time at Finnerty's, where he had drinks on the owner of the bar, which has become a gathering spot for Giants fans.
Giants senior vice president of marketing Tom McDonald said the entire event, a joint venture to help promote the Fan Cave and the club's trip to New York, was a success.
"Any time you can run a promotion like this that engages fans and that gets the word out, and creates some buzz around the Giants and Major League Baseball, I think it's a plus," McDonald said.
The 14,000 responses McDonald received came within one week of the promotion being announced. He noted how well the Giants fans have responded to social media interaction with the team, and last week's sweepstakes was no different.
"If you can create an experience for a fan and make it unique, like a chance to go to New York City to see a Giants game, it's something you want to see happen," McDonald said. "And by all accounts, he had a great time."
Portilla affirmed that, noting a tie between Friday's game and Saturday's visit to the Fan Cave for his favorite part of the weekend.
Sitting so close to Buster Posey, who was playing first base, was enough thrill for Portilla. Then, his uncertainty about what the Fan Cave would bring turned to complete enjoyment.
"I didn't really know what to expect or what it was going to be like," Portilla said. "But it was just so much fun. They're just the luckiest people to do that on a daily basis."
AJ Cassavell is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.