Panzarella received 65% of the vote, according to unofficial numbers from the Harris County Clerk's Office.
The seat was in play after Councilmember Abbie Kamin resigned to run for Harris County Attorney.
That move triggered a special election, but when none of the 7 candidates reached 50% of the vote, the election went to a runoff.
The district spans many of the City of Houston's well-known areas, including The Heights, Montrose, and Meyerland.
Over 9,900 voters voted in the runoff election, according to the Harris County Clerk's website.
The winner will play a part in the city's 2027 fiscal year budget process.
The election results are expected to be certified and the winner sworn in in May.