The gap between Keelung's ruling KMT mayor and his DPP challenger is narrowing, bad news for an incumbent who once looked safe and a boost for the opposition.

• Sitting mayor Hsieh Kuo-liang is defending a seat in a city that leans blue, but his lead has shrunk.
• Damage from a preschool abuse scandal and heavy flooding has hurt him, along with the earlier recall fight.
• Challenger Tung Tzu-wei, the city council speaker and a relative of President Lai Ching-te, is running as the heir to popular former mayor Lin Yu-chang.
• Tung leads steadily with voters in their thirties and pushed the mayor into more than doubling the cash gift for seniors.
• Both sides are bringing in star power: KMT mayors from Taipei and Taichung for Hsieh, former president Tsai Ing-wen chairing Tung's campaign.

Outlook: Swing voters and younger residents will decide the race, and Hsieh will likely keep leaning on steady-hand governance and cash handouts to hold his edge.