Rapid Reaction: Red Sox 5, White Sox 4

BOSTON -- John Farrell says there is a lot of potential with the rookies at the bottom of the order, but the Boston Red Sox manager has also warned that there will be growing pains. Wednesday night's 5-4 walk-off victory over the Chicago White Sox was a trial by fire.

Mookie Betts came up clutch in the bottom of the ninth inning by getting hit by a pitch to reach base, and then coming all the way home on pinch-hitter Daniel Nava's double high off the wall to knot things at 4-4 for the Red Sox.

With the winning run at second, Brock Holt pulled Javy Guerra's 95-mph four-seamer through the right side of the infield, scoring Nava for a walk-off win in what continues to build on a wild rookie season for the utility man.

On Wednesday night, Holt started at shortstop, the sixth different position he has played this season. The walk-off single was his lone hit of the night, making him 11-for-42 on this final homestand before the All-Star break.

After early struggles, the Red Sox finally got on board in the eighth to start the rally. Mookie Betts led off the inning with a rare infield double. He beat out the shortstop's throw to first, then alertly took second with no one covering the bag, sliding headfirst to avoid a belated throw and tag attempt. He was singled home by Pedroia, who took an up-and-in fastball back up the middle.

David Ortiz then launched reliever Jake Petricka's high fastball high off the Green Monster for a double, scoring Pedroia. After Mike Napoli walked, Jonny Gomes sent Ortiz home from second by pulling a line drive down the left-field line into the corner.

Vazquez debuts at catcher: By designating A.J. Pierzynski for assignment earlier Wednesday, the Red Sox made it clear that they are invested in Christian Vazquez as the future behind the dish. Manager John Farrell called Vazquez a player "long on potential," and he showed flashes of it defensively in his debut.

After flying out to right in his first major league at-bat in the bottom of the third, he came out in the top of the fourth and showed off his arm. Following an error by first baseman Mike Napoli on a ball hit by Dayan Viciedo, right fielder Betts fired a throw home that was too late to nab Conor Gillaspie. But Vazquez fired immediately back to second, where Holt applied the tag on Viciedo in time for the out.

In the seventh, Red Sox left fielder Johnny Gomes misplayed a deep Tyler Flowers fly ball off the scoreboard in the left-field corner but made an impressive throw home that Vazquez got down just in time to tag out Alejandro De Aza.

De La Rosa's serviceable outing: Rubby De La Rosa got the spot start Wednesday for the Red Sox after throwing one inning Sunday for Pawtucket. He looked shaky early, then settled down before getting relieved by Craig Breslow in the sixth. De La Rosa gave up six hits, three earned runs and two homers while striking out three, throwing 84 pitches (54 for strikes) over five innings of work.

He appeared to struggle with his changeup. Half of the hits he scattered came on this pitch, including Jose Abreu's solo home run to dead center in the first inning.

JBJ keeps flashing leather: Jackie Bradley Jr. continues to have a knack for the highlight reel worthy plays in center. In the second inning, the youngster got a great jump on Tyler Flowers' shot to the right-center gap and laid out for the diving snag.