BALTIMORE (Interstat) — Jeremiah Jackson launched a grand slam and a solo home run, Pete Alonso delivered a go-ahead two-run shot in the seventh inning, and the Baltimore Orioles stormed back from a six-run deficit to stun the Arizona Diamondbacks 9-7 on Monday night at Oriole Park at Camden Yards.

In a game that flipped from a potential Arizona rout to a stunning Baltimore comeback, the Orioles sent an announced crowd of 10,289 home exhilarated after a two-hour, 48-minute rollercoaster. The victory pushed Baltimore’s record to 9-7, while Arizona fell to 9-8.

The Diamondbacks, defying pregame projections that favored the Orioles, built what appeared to be a commanding lead early. Ketel Marte set the tone, driving the game’s fourth pitch from Baltimore starter Dean Kremer over the right-field wall for a leadoff homer. Marte struck again in the third inning, taking Kremer deep once more for another solo shot, his fourth of the year, to make it 2-0.

Arizona’s offense continued to pressure Kremer in the fourth. Jose Fernandez reached on a two-out error by shortstop Gunnar Henderson, bringing Nolan Arenado to the plate. Arenado, who entered the game with just one home run on the season, connected on a Kremer offering, sending a two-run homer to left field to extend the lead to 4-0.

Kremer settled to complete five innings, allowing two earned runs on six hits while striking out nine, but the damage appeared significant. Arizona starter Ryne Nelson, meanwhile, was largely effective, limiting the Orioles to one run through five frames. Baltimore’s lone early tally came in the third when Blaze Alexander reached on catcher’s interference and scored on a triple by Henderson.

The game seemed to slip entirely from Baltimore’s grasp in the top of the sixth against reliever Albert Suárez. Adrian Del Castillo singled and Ildemaro Vargas doubled, setting the stage for Arenado once more. The veteran third baseman crushed a three-run homer to center field, his second of the night, giving him five RBIs and pushing the Arizona advantage to 7-1.

What followed was the most important sequence of the contest: a stunning and immediate rebuttal by the Orioles that changed the game’s trajectory. In the bottom of the sixth, Pete Alonso led off with a double against Nelson. After a strikeout, Dylan Beavers singled and Leody Taveras followed with an RBI single to make it 7-2. A walk to Colton Cowser loaded the bases for Jeremiah Jackson.

Facing reliever Taylor Rashi, Jackson worked the count and then unloaded on a 2-1 pitch, driving it deep to left field for a monumental grand slam. The four-run blast, Jackson’s second homer of the year, suddenly brought Baltimore within a run at 7-6 and electrified the home crowd.

The momentum had irrevocably shifted. In the seventh, with Jonathan Loáisiga on the mound for Arizona, Taylor Ward was hit by a pitch. Alonso then stepped in and powered a first-pitch fastball over the wall in left-center field for a two-run homer, his second of the season, vaulting the Orioles into an 8-7 lead.

Jackson provided a critical insurance run in the eighth, leading off the inning with a towering solo homer to center off Loáisiga, completing his five-RBI night and setting the score at 9-7.

Baltimore’s bullpen, after Suárez’s rough sixth, locked the door. Rico Garcia worked a scoreless seventh. Closer Ryan Helsley took over in the ninth and was dominant, striking out two in a perfect frame to secure his fifth save of the season.

Suárez (1-0) was credited with the win despite allowing three earned runs in two innings of work. Loáisiga (0-1) took the loss for Arizona, surrendering three earned runs on three hits in one inning.

The Orioles managed only eight hits to Arizona’s ten, but their hits were devastatingly timely. The comeback negated a strong offensive night for the Diamondbacks, led by Arenado’s three-hit, five-RBI performance and Marte’s two solo homers.

The two teams will continue their three-game series on Tuesday night at Camden Yards.