For the first time since December of 2010, Toyota’s luxury brand, Lexus, sold more cars in the U.S. last month than German rivals BMW and Mercedes-Benz. Lexus delivered 24,237 vehicles in August, compared to 16,835 from BMW (excluding MINI) and 22,686 from Mercedes-Benz (excluding Smart).

Year to date, the picture looks a bit different, with Lexus’ 150,604 units lagging behind BMW’s 164,636 and Mercedes’ 182,077. As Bloomberg says, it’s unlikely that Lexus can make up enough ground in the four remaining months of 2012 to overtake either rival automaker.

Lexus’ sales were up by some 34-percent in August, which is quite a bit more impressive than the 11-percent gain realized by Mercedes-Benz. Things at BMW aren’t so bright, as August sales fell by 19-percent. A lack of incentives and tight inventory supply were apparently to blame.

Don’t count BMW out just yet, as Ludwig Willisch, head of BMW North America, claims the brand has “ambitious plans for the months ahead,” to “capitalize on increasing sales momentum.” Excluding August, we presume.

As for Lexus, the brand attributes its August success to a mix of factors, including the introduction of the new ES sedan and brisk sales of the revised GS sedan. The brand’s annual “Golden Opportunity” sales event likely lured buyers on the fence into dealerships, further helping to pad August numbers.

As any company that makes a living selling product will tell you, however, padding one month’s numbers usually comes at the expense of the following month’s sales. The challenge for Lexus becomes delivering impressive September sales in the absence of buyer incentives.