Former Makati City acting mayor Romulo "Kid" Valderama Peña Jr. pulled off a massive upset win over Vice President Jejomar Binay in Makati City's 1st district congressional race on Monday, based on the latest partial and unofficial results from the Commission on Elections (Comelec) Tuesday morning.

Peña, a member of the Liberal Party, had 71,035 votes, ahead of Binay's (United Nationalist Alliance) 65,229 votes, in 99.8% of all election returns (502 of 503 clustered precincts) in the district transmitted to the Comelec.

Binay's daughter, reelectionist mayor Abby Binay, earlier defeated her brother Junjun Binay in Makati City's mayoral race, based on partial and unofficial results.

• Abby Binay beats brother Junjun for Makati's top post

Abby got 178,154 votes, while her brother Junjun had 97,827 votes, based on 99.2 percent of election returns of clustered precincts, as of 1:19 a.m. Tuesday.

The siblings' relationship soured when Junjun filed his certificate of candidacy to run for mayor against his sister last year.

Their mom Elenita and sisters Nancy and Anne took the side of Junjun, while their father Jejomar sided with Abby.

Abby earlier claimed Junjun broke an agreement that he would not run for the business district's top post.

Junjun, a former mayor of Makati, however, said there was public clamor for him to return.

Before assuming mayoralty in 2016, Abby represented Makati's 2nd District for three terms.

She decided to run against then acting mayor Peña after Junjun was dismissed from his post in 2015 for allegations of irregularities in city project contracts entered by his administration.

The partial and unofficial tally is sourced from the Comelec Transparency Server.

Click here for ABS-CBN's election results: