This happened in *Catching Fire*, the second book in the *Hunger Games* trilogy. When the Capitol announced that the tributes from each district would be fighting in a special "Quarter Quell" edition of the Games, Peeta was distraught. He believed his death would bring a quicker end to the Games and potentially save Katniss.
He pleaded with Haymitch, "I'm not asking for a victory... just a chance to live long enough to try."