Yan Feng, a pediatrician from Beijing, just paid $2.3 million for a townhouse on Convent Avenue in the Hamilton Heights neighborhood in Harlem, bidding $100,000 more than the asking price after losing out on another deal for a house down the street.

Now Ms. Feng and her husband, Stanley Cha, a securities lawyer, have an eye out for other townhouses in the neighborhood as second homes for friends from Beijing, and they are looking for commercial investments in the neighborhood as well.

Their purchase of the 20-foot-wide house with an unusual stepped brick gable is part of a recent renaissance of the Harlem real-estate market that is bringing in new buyers for both century-old townhouses and new condominiums across Harlem following the worst of the financial crisis.

After a long chill in the market, there has been a resurgence of the sales of townhouses, with three townhouses closing between $2.3 million and $2.85 million, the highest prices since the spring of 2009.

The most expensive single townhouse sale since 2007—a meticulously renovated loft-like house on West 122nd Street—closed on Sept. 30.