Puerto Rico Gov. Pedro Pierluisi conceded defeat Sunday night after losing a primary election against Rep. Jenniffer González, the island’s resident commissioner and nonvoting member of Congress, effectively ending the governor’s re-election bid.

In a speech, Pierluisi labeled the defeat as “very painful” and unexpected while also congratulating González on her win and wishing her success as the gubernatorial candidate for Puerto Rico’s ruling party, the New Progressive Party, or PNP, which favors statehood.

With 76% of the votes counted early Monday morning, González obtained 136,281 votes (56%) while Pierluisi got 105,548 (44%), according to Puerto Rico’s electoral commission.

The surprise upset came four years after González and Pierluisi ran on a joint ticket to win their current seats. At the time, they presented a united front as they attempted to clean the party’s image following the resignation of disgraced pro-statehood governor Ricardo Rosselló after being marred in scandal over leaked private chats.

Unlike the U.S. mainland, political parties on the island are based on ideals about Puerto Rico’s territorial status. But as a U.S. territory, Puerto Rican public officials often need to align with a mainland party.

While Pierluisi and González both belong to the pro-statehood party, Pierluisi is a Democrat and González is a Republican.

González celebrated her win alongside crowds of cheerful supporters.

“Today is a special day for me, for my family, for my team and for all Puerto Ricans who opted for change,” González said. “I am going to be a governor who is going to be on the streets all the time.”

González is the first female gubernatorial candidate to secure a primary win for the New Progressive Party. Puerto Rico elected Sila María Calderón of the Popular Democratic Party, or PPD, as its first female governor in 2000.

The PPD, which supports the island’s current territorial status, also had its primary Sunday. Puerto Rico Rep. Jesús Manuel Ortiz Jesús Manuel Ortiz defeated Sen. Juan Zaragoza by a wide margin.

Ortiz and González will face each other and third candidate Juan Dalmau of the Puerto Rican Independence Party, or PIP, in the general election on Nov. 5.

As results trickled in late Sunday night, the electoral commission’s website crashed, frustrating many who were closely following the primaries.

Officials said they rushed to fix the problem, saying they did not know what caused the site to crash but that U.S. Homeland Security and other agencies were helping.

“If it were necessary to activate the FBI given the situation, we will do it,” said Jessika Padilla, the commission’s interim president.

Power outages were also reported at more than a dozen voting centers, including one where Ortiz arrived to cast his vote. The outages forced officials to revert to a manual process. Power outages have become increasingly more common in Puerto Rico as the U.S. territory awaits the reconstruction of its power grid since Hurricane Maria hit Puerto Rico in 2017.

Aware of this, officials of Puerto Rico’s electoral commission rented more than a dozen generators and a private power company identified 81 alternate voting sites with guaranteed electricity.