Confirmation:
http://sfgate.com/cgi-bin/article.cg...s210200D85.DTL
1969 — Pinch-hitter Rich Reese hit a grand slam to power the Minnesota Twins to a 5-2 victory over the visiting Baltimore Orioles and end Dave McNally's 15-game winning streak. His two victories at the end of 1968 had given him 17 straight wins.