On June 26, 1963, Tim Harkness hit a dramatic game-winning grand slam in the bottom of the 14th inning.
Trailing 4-0 in the sixth inning, the Mets mounted a two-out rally. Ron Hunt singled and scored on a double by Duke Snider, then Frank Thomas homered to cut the Cubs lead to a single run. Two innings later the Mets tied the game after an RBI single single by Thomas.
The two teams stayed tied until the 14th inning when the Cubs scored a pair of runs to take a 6-4 lead.
Jim Hickman and Ron Hunt led off the Mets half of inning with back-to-back singles. But it cost the Mets when Hickman was thrown out at third base trying to take the extra base. With one out, Jimmy Piersall walked to put runners at first and second. After Thomas flied out reducing the Mets to their final out, Sammy Taylor walked to load the bases. Tim Harkness had three hits in six at-bats on the day including a double. He worked the count full against Cubs reliever Jim Brewer, then ripped a line into the right-field seats to give the Mets a miraculous 8-6 win.