When you're the Philadelphia Phillies, and you have Roy Halladay scheduled to go up against the Houston Astros in your home and season opener, you're probably feeling pretty good about your chances. But while the Phillies ended up getting their win, the course they took to get there was anything but predictable.

After falling behind and trailing 4-0 in the seventh inning, the Phillies clawed away and walked off in the bottom of the ninth after Astros closer Brandon Lyon couldn't slam the door.

Halladay and Brett Myers traded zeroes into the sixth inning, when Bill Hall drove in the game's first run with a grounder. The Astros weren't done, though, and in the seventh added three more on a two-run triple by Michael Bourn and a sac fly by Angel Sanchez. Needing just nine more outs, the Astros found themselves in a good position.

But the Phillies got two back in the bottom half, and then quickly got to work against Lyon in the ninth. Behind 4-2, Jimmy Rollins led off with a single, and Ryan Howard followed with a single of his own. After a pop out, Ben Francisco hit another single to score Rollins from third, and then Carlos Ruiz hit another single to load the bases.

At that point, the tying run was just 90 feet away, and Wilson Valdez wasted little time tying things up, ripping a first-pitch slider into left. That brought John Mayberry to the plate as a pinch-hitter, and on a 2-2 pitch he hit a liner over Bourn's head in center field. Mayberry got credit for a single, Francisco came home, and the stadium erupted in celebration of the Phillies' dramatic comeback.

For the Astros, this is about as demoralizing as it gets, although they can take some solace in the fact that other N.L. Central closers John Axford and Ryan Franklin also blew saves on Thursday. The series continues Saturday, with Wandy Rodriguez and Cliff Lee.

For more on the Astros and Phillies, please check out team blogs Crawfish Boxes and The Good Phight.