St. Louis Cardinals at Arizona Diamondbacks: Final Score & Recap

The Arizona Diamondbacks defeated the St. Louis Cardinals 5-3 at Chase Field on July 18, 2026, with the DiamondIQ model's estimate of a home win climbing from a pre-game 52 percent all the way to 100 percent by the final out. Arizona built its winning margin almost entirely in the early innings, scoring once in the second and three times in the third before adding a fourth run in the fourth, which left the Cardinals chasing a deficit they could never fully close despite a two-run sixth and a run in the ninth.

The third inning was the game's decisive sequence. Nolan Arenado's double off Dustin May delivered the single largest win-probability swing of the night at plus 12.9 percent, and Gabriel Moreno followed with a single that added another 8.4 percent. Corbin Carroll partially blunted the rally by grounding into a double play, a play that swung 8.4 percent in St. Louis's favor, but the damage was already done. James McCann's second-inning single off May, worth plus 6.1 percent, had set the tone earlier. The Cardinals' most meaningful response came in the sixth, when Lars Nootbaar singled off Brandon Pfaadt to spark a two-run frame worth plus 6.2 percent, though Arizona's bullpen held firm from there.

Among individual performers, Arenado finished as the game's top batter by the DiamondIQ model's accounting, posting a combined WPA of plus 14.1 percent and an RE24 of plus 1.4. Moreno was nearly as impactful at plus 10.8 percent WPA and plus 1.1 RE24, while Ketel Marte contributed plus 6.4 percent WPA and a team-high plus 1.3 RE24. On the mound, Ryan Thompson led Arizona's relievers at plus 5.7 percent WPA, followed by Kevin Ginkel at plus 4.5 percent, with starter Brandon Pfaadt adding plus 3.6 percent despite allowing the Cardinals' sixth-inning burst.