SF Marathon 10K: Luisa Tsang Owns the NB35-39 Field

• Solo winner: Luisa Tsang, age 35 out of Richmond, CA, crossed in 1:14:59 — the only finisher in the NB35-39 field.
• Pace: Tsang averaged 12:04/mi across the 10K course.
• Conditions: Race day brought a cool 64°F under overcast skies with 7 mph wind and 81% humidity along the San Francisco waterfront.

There are days when you race the clock, the course, and the conditions — and Luisa Tsang did exactly that on Sunday morning in San Francisco. With no one else toeing the line in the NB35-39 field, Tsang made the 10K entirely her own, finishing in 1:14:59 at a steady 12:04-per-mile pace through the city's characteristically cool, humid air.

That finish time is the number that defines NB35-39 in the 2023 SF Marathon 10K, full stop. Tsang showed up, covered the distance, and took the win — and in a race where the overall men's course record sits at 32:28 (set by Gudisa Ayano in 2022), simply getting to that finish line on the hilly streets of San Francisco is its own accomplishment. Tsang did it, and the NB35-39 title is hers without question.