The Cubs had lost five out of six when they faced the Montreal Expos in a doubleheader Sunday, June 22, 1969 and had seen their lead in the N.L. East drop from nine games to six.
They won the first game 7-6. The game ran two hours, 49 minutes, which might not seem like a long time to you in 2019, but in 1969, that was one of the longer games of the year (the longest nine-inning game that year by time was 3:22).