In 1999, he became the first African-American to run a Busch Series race, when he ran at Watkins Glen in the No. 8 Dura LubeChevrolet Monte Carlo owned by Bobby Hillin Jr.. He started 24th and ran near a top-ten most of the day before an accident relegated him back to 21st. The next season, he made his Craftsman Truck debut at Portland, starting 31st and finishing 24th in the No. 23 Red Line Oil truck owned by Team 23 Racing. He also competed against Bobby Norfleet in that race, marking the only time in NASCAR two African-Americans have competed in the same race. He ran five races the next season in the No. 4 for Bobby Hamilton Racing, his best finish an eighteenth at Phoenix International Raceway. In 2002, he ran in the Craftsman Truck series full-time for Hamilton. While he did not finish in the top-ten, he had sixteen finishes between 11th-18th, leading to a seventeenth-place points finish and runner-up to Brendan Gaughan for NASCAR Craftsman Truck Series Rookie of the Year. The next season, he grabbed his first career pole at Lowe's Motor Speedway and had a tenth-place run at Kansas Speedway, garnering a 14th-place finish in the championship standings. He switched over to Bill Davis Racing in 2004. He had a best finish of tenth and finished 22nd in points. In 2005, he won two consecutive poles, and had his first top-five finishes. Lester raced in his first Nextel Cup race in the Golden Corral 500 at Atlanta Motor Speedway, driving the No. 23 Waste ManagementDodge Charger for Davis in 2006. The race was supposed to be run on March 19, but was postponed for a day due to rain. He qualified 19th, becoming the first African-American to make a Cup race since 1986, and the sixth in series history. He finished 38th, six laps down. He ran another race that season at Michigan, finishing 32nd. He later DNQed at California after spinning in qualifying. After failing to finish in the top-ten in 2006, Lester departed Davis to drive the No. 15 Billy Ballew Motorsports Chevy. His best finish was an eighth at Kentucky, when he stepped out of the truck due to sponsor problems. He left NASCAR racing at the end of 2007.
In 2008, Lester drove the No. 3 Riley Daytona Prototype for Southard Motorsports in the Grand-Am Rolex Sports Car Series, partnering with Shane Lewis. He moved to Orbit Racing for 2009, finishing 3rd at the summer Daytona race. The next year, Lester moved to a new team in Starworks Motorsport driving the No. 7 BMW Riley for the full season, finishing 17th in points. For 2011, Lester moved to the GT category with Autohaus Motorsports and their Chevrolet Camaro team. On May 14, 2011, Lester made sports car history by becoming the first African-American driver to win in any Grand-Am division. Fittingly, Lester won at the Virginia International Raceway, located close to the home of NASCAR's first African-American winner, Wendell Scott.
Personal life
Lester lives in Windermere, Florida with his wife Cheryl, and their sons William Alexander IV and Austin Richard.