Arizona Diamondbacks at Chicago Cubs: Final Score & Recap

The Chicago Cubs defeated the Arizona Diamondbacks 8-4 at Wrigley Field on May 3, 2026, a result the DiamondIQ model's estimate largely anticipated, having installed the Cubs as 70% pregame favorites before the probability climbed to certainty by the final out. Arizona's Merrill Kelly absorbed the bulk of the damage, surrendering the game's two most consequential blows in back-to-back innings. Moisés Ballesteros delivered a home run in the bottom of the third that swung win probability 17.3 points in Chicago's favor, and Michael Busch followed in the fifth with a triple that added another 15.0 points, effectively sealing the outcome against a Diamondbacks offense that never sustained enough pressure to threaten. Arizona had briefly shown life in the top of the second, when Gabriel Moreno's home run off Matthew Boyd shifted the advantage 8.8 points toward the visitors, but Jose Fernandez grounded into an out later in the frame that swung probability 8.2 points back toward Chicago, cooling the Arizona threat before it could fully develop.

On the individual ledger, Ballesteros finished as the game's most impactful performer at the plate, accumulating a WPA of plus-21.3 and an RE24 of plus-1.6, while Busch was nearly as influential at plus-19.2 WPA and plus-0.9 RE24. The Cubs scored in five of their nine half-innings, including a three-run fifth that put the game beyond reach, and matched that with a two-run seventh to build the final margin. Chicago's bullpen held the line cleanly in the late innings, with Phil Maton and Ryan Thompson posting WPAs of plus-2.9 and plus-0.7 respectively to close out Arizona's final attempts, including a two-run top of the ninth that came far too late to matter.