On May 18, 2011 — Five different games end in shutouts today. The most remarkable performance is a three-hitter thrown by Jake Peavy of the White Sox, making only his second appearance since undergoing shoulder surgery 10 months earlier. He wins 1 – 0 over Cleveland, with Justin Masterson being saddled with the loss in spite a solid performance of his own. Boston also wins 1 – 0, over Detroit, with Clay Buchholz getting the win, and, in another whitewash, Charlie Morton of Pittsburgh notches his second career shutout. The Mets and Mariners also win with combined shutouts.
Source:
Baseball Reference May 18