Nolan McLean delivered a pitching performance that deserved a win, but the New York Mets' bullpen and offense couldn't hold up their end of the bargain in a disheartening 7-1 loss to the Arizona Diamondbacks on a chilly Thursday night at Citi Field.

For six masterful innings, McLean silenced the Diamondbacks' bats, weaving a gem that had the home crowd buzzing. His only obstacles were a walk, a single, and a climbing pitch count that forced his exit with a narrow 1-0 lead. It was the kind of start that can define a series and build momentum for a team.

Unfortunately for the Mets, the game unraveled the moment he left the mound. What had been one of baseball's most reliable bullpens, entering the night with a stellar 1.71 ERA, was blitzed for seven runs across the seventh and eighth innings. A potential series victory swiftly dissolved into a frustrating defeat.

The collapse began in the seventh. Reliever Luke Weaver, who had been flawless this season, entered with two runners on. A sharply lined changeup to right field proved too tough to handle, caroming off the wall for a game-tying double. The very next play saw a costly throwing error on a ground ball, allowing Arizona to seize a lead they would not relinquish.

The Diamondbacks capitalized on the momentum shift, adding a sacrifice fly and an RBI triple to break the game open at 4-1 before piling on three more runs in the eighth. Meanwhile, the Mets' offense, which mustered only three total runs over the final two games of the series, went quietly into the night.

This loss stings beyond the final score. It wastes a brilliant effort from a starting pitcher and halts the team's early-season momentum. The Mets, now 7-6, will need to quickly regroup, tighten their defense, and reignite their bats to turn promising starts into decisive wins.