Napoleonic Quiz - And the answer is....

... the Battle of Essling 

You can read more details in Wikipedia, but here a little summary:

"In the Battle of Aspern-Essling (21–22 May 1809), Napoleon attempted a forced crossing of the Danube near Vienna, but the French and their allies were driven back by the Austrians under Archduke Charles. The battle was the first time Napoleon had been personally defeated in over a decade, but it was no more than a tactical victory for the Austrians, who failed to capitalise on their superior numbers and merely repulsed Napoleon, without defeating him."

Well, as I said in the previous post may be not a defeat, but clearly not a victory.