The Major League Baseball season is quite long, but after the Colorado Rockies’ first two games last weekend, some fans had begun to worry: Star shortstop Troy Tulowitzki—who signed a 10-year, multimillion dollar contract last year—hadn’t hit a good ball. That changed Tuesday night at Coors Field when he knocked a home run to center field that led the Rockies to a 3-0 win over the Los Angeles Dodgers (full game recap via Purple Row).

The game-changer for Tulo? A walk-up song switch from Katy Perry’s “Firework” to Justin Bieber’s “Baby” (Denver Post). It also helps when you have offensive backup from a guy like Chris Iannetta, Colorado’s starting catcher, who’s in a make-or-break season to hold on to his job. Perpetually underperforming, Iannetta has started 2011 on a tear, hitting .444 and claiming extra bases on three of his four hits ( Jhoulys Chacin was also key to last night’s win: The 23-year-old pitcher allowed just five hits and two walks in seven innings, and threw four strikeouts (Reuters).