From pool cleaning to bank loans to making brushes, three small companies are finding ways to thrive against much larger competitors.

VivoPools vs. ASP (America’s Swimming Pool Co.)

The challenge: Bringing reliability, top-notch service, and panache to pool maintenance.

What he did: Willan Johnson spent 20 years frustrated by the slapdash, small-time contractors maintaining his pool near Los Angeles. In 2009, Johnson opened his own alternative — VivoPools — where he’s making a splash with high-end service, online scheduling, and spiffy-uniformed workers. Previously employed by a search-marketing firm, Johnson, 48, raised funding from fellow Internet industry veterans and quickly hired a team with expertise in pools. With operations up and running in Arizona, California, Florida, Nevada, and New Jersey, he’s now going up against America’s Swimming Pool Co., a franchise serving 12 states. Vivo, which has begun franchising, brought in about $6.8 million in sales last year and has attracted clients like W Hotels.

Biz2Credit vs. Citibank

The challenge: Transforming the misery of applying for a bank loan into a streamlined, efficient online process.

What they did: Many entrepreneurs gnash their teeth at the paperwork required for a bank loan — especially if they are rejected and have to start all over at another institution. Seeing the need for an alternative, Rohit Arora, 37, left a consulting career at Deloitte to launch Biz2Credit with his brother Ramit, 33, in New York City in 2007. After borrowers enter their data in Biz2Credit’s simple online interface, it matches them with lenders — often smaller banks — whose criteria they meet. (Biz2Credit gets a small cut.) “It saves owners a lot of time and effort,” says Rohit. The brothers, from Delhi, initially targeted underserved immigrants, who quickly spread the word. Sales rose from $4 million in 2011 to $9.5 million in 2012. Now banks want to license Biz2Credit’s technology.

Anisa International vs. Albéa

The challenge: Carving out a niche in the ferociously competitive cosmetics and grooming industry.

What she did: Working in her mother’s export firm, Anisa Telwar stumbled across a chance to help a Korean manufacturer sell cosmetics brushes in the U.S. She quickly discovered a passion for the product — and, in 1992, at 26, launched Anisa International, a design, distribution, and manufacturing business for brushes, cosmetics bags, and accessories. Today the picture is pretty for Anisa, which expected $30 million in annual sales for 2012 while taking on global cosmetics packaging giant Albéa. One smart move: buying a factory in China. That makes it easy to design custom brushes for clients such as Sephora and Estée Lauder. “To me, it is a true art,” Telwar says. Anisa is also teaming with DuPont to develop a new synthetic fiber that performs like costlier natural ones.

This story is from the April 29, 2013 issue of Fortune.