Call it a Supreme mistake.

Diana Ross was convicted Monday in Tucson of driving under the influence and was sentenced to two days in jail.

The 59-year-old R&B vocalist's sentence was meted out over the phone. Ross called into the hearing from New York and pleaded no contest to the DUI charge. As a result of her plea, two other, more serious charges were dropped, the Associated Press reports.

Ross was arrested on Dec. 30, 2002, after police were alerted to a car traveling in the wrong lane outside the city limits. A breath test revealed Ross's blood-alcohol concentration to be 0.20 percent, more than double Arizona's 0.08 percent legal limit for driving.

The singer's original charges included DUI, driving with a blood-alcohol concentration of 0.08 percent or more, and extreme DUI, which is charged in Arizona when the driver's blood-alcohol concentration exceeds 0.15 percent.

According to the police report filed at the time, Ross was unable to walk a straight line and fell while trying to stand on one leg and count to 10.

Ross, who had voluntarily entered drug and alcohol rehabilitation in early 2002, must serve 48 hours in jail before March 9, after which she will be subject to a year of unsupervised probation.