With an 8th-inning homer against the Diamondbacks, Cubs slugger Sammy Sosa extends his major league record for home runs in a month, hitting his 20th round-tripper in June. The Cubs lose to the Diamondbacks, 5 – 4.

This Day In Baseball

On June 30, 1998 With an 8th-inning homer against the Diamondbacks, Cubs slugger Sammy Sosa extends his major league record for home runs in a month, hitting his 20th round-tripper in June. The Cubs lose to the Diamondbacks, 5 – 4.

Source
Baseball Reference June 30