The 35-year-old's Rastriya Swatantra Party (RSP) was also leading in proportional representation vote, according to results declared and election commmision trends.

The vote was the first since deadly September 2025 youth anti-corruption protests toppled the government.

Shah himself had on Saturday defeated the veteran four-time prime minister KP Sharma Oli -- whose Marxist-led government was ousted in the violence last year -- in his own seat.

His victory over the 74-year-old Oli, and his rise from the capital's mayor to potential prime minister, marks one of the most dramatic results in recent Nepali politics.

The September 2025 youth-led demonstrations, under a loose Gen Z banner, began over a brief social media ban but quickly tapped into broader grievances over corruption and a struggling economy.

Elections on Thursday chose a new 275-member House of Representatives, the lower house of parliament, with 185 seats chosen directly, and 110 by a proportional representation vote.

On Saturday morning, there were 125 of the direct elections declared: RSP dominating with 98, Nepali Congress 14, the Maxists of now-defeated Oli trailing with seven.

Former Maoist guerrilla commander Pushpa Kamal Dahal, a three-time prime minister, won his seat, with his party holding three in total.

Trends showed that Shah's RSP was also leading in 27 of the remaining 40 constituencies in the direct elections.

In the proportional representation vote, RSP were leading with nearly half of the counted votes -- but final results could take several more days.

Nepali Congress, the largest party in the past coalition government, also saw its new leader, Gagan Thapa, defeated by RSP.

"Counting is moving forward smoothly in all remaining constituencies," Election Commission spokesman Narayan Prasad Bhattarai told AFP.

"Results of all direct votes are expected by end of today, the PR (proportional representation) votes will take a few days more."

The first-time parliamentary lawmaker Shah toured the streets of his new constituency on Saturday evening, wearing his signature dark sunglasses and waving from the sunroof of a car in a victory parade through cheering crowds who chanted "Balen" -- as he is better known.

Shah, who did not make a speech, won over three times more votes than Oli, who congratulated the winner, wishing him "a smooth and successful five-year tenure".