On May 8, 1970 — A record 30 home runs are hit by National League players in seven games, including two apiece by each of five players. The 20 MPH wind at Wrigley Field produces nine homers as the Cubs defeat the Reds, 10 – 7, snapping the Reds’ win streak at eight games. Hal McRae and Tony Perez have a pair for the Reds, while Billy Williams has two for Chicago.

Source:
Baseball Reference May 8