Janowski often fell victim to Lasker's psychological preparation. In the last round of Cambridge Springs 1904, Lasker had to win with Black pieces to catch up with Janowski... and he did exactly that.
In 1905, Janowski played a match against Marshall. He played several good games, but his playing, as usual, was often marred by incredible mistakes.
In the 11th game, Janowski tried a curious pawn sacrifice, got good counterplay, but decided to "play for loss" (Tarrasch's characterization of many of his games) and succeeded.
A very interesting game from the Ostende tournament. Both players played with much imagination. Janowski adamantly refused to believe that Bernstein's Knight sacrifice was correct!
Janowski had a clear way to win against Znosko-Borovsky, but he wanted to checkmate him, and ultimately lost.
Two other, almost textbook examples of "How to draw a won position".