Rapid Reaction: Cubs 4, Phillies 3

Here’s a quick look at the Chicago Cubs' 4-3 victory over the Philadelphia Phillies on Saturday:

How it happened: Starlin Castro hit his first home run in exactly a month to give the Cubs their first lead of the day in the sixth inning, and it would hold up as five relievers helped shut down the Phillies over the final five innings of the game. The Cubs trailed three times but fought back with single runs in the second, third and fifth innings before Castro’s winning homer. Cole Gillespie had a hit and sacrifice fly to drive in two runs, while Welington Castillo’s base knock in the third inning was one of three times the Cubs tied the game before taking the lead for good. Kevin Frandsen homered for the Phillies, who also got RBI hits from Carlos Ruiz and Michael Young. The teams played sloppy early, but the Cubs settled down as Carlos Villanueva, James Russell, Blake Parker, Pedro Strop and Kevin Gregg came on in relief of Chris Rusin to secure the win. Combined, they gave up two hits.

What it means: Before the game, manager Dale Sveum was lamenting the fact the Cubs had blown so many leads this season -- especially at home.

Maybe the bullpen heard his words, because it came up big.

Sveum used four different pitchers to retire four consecutive batters in the seventh and eighth innings. The strategy worked, as Russell took care of lefty Chase Utley, and Sveum's right-handed relievers did the same to the right-handed Phillies. For one of the few times this season, the Cubs grinded out a home win.

Outside the box: The Cubs will get some reinforcements as rosters expand on Sunday, but only a couple of players are sure things to be called up right now.

Ryan Sweeney will be activated from the disabled list and Luis Valbuena shouldn’t be far behind him. Expect Brooks Raley to join Russell in the bullpen as another lefty option, but Sveum said the final call-ups haven’t been determined yet. Don’t expect an influx of players, as several from Triple-A Iowa are already here. Third baseman Mike Olt would be an interesting option, but he’s struggled for much of this season.

What’s next: The rubber game of the series takes place on Sunday when Jake Arrieta (2-3, 5.91 ERA) takes on Kyle Kendrick (10-11, 4.40).