With the All-Star break looming this year, it's hard to believe that the Astros are actually higher in one of baseball's toughest divisions than the Red Sox are in the mediocre AL East as these teams open a three-game set Friday night in Houston.It's been a stunning turn of events since Boston (41-51) captured its third World Series title in 10 years in 2013 -- the same year Houston (39-54) finished with a franchise-worst 51 victories, also an MLB-low.Now only 2 1/2 games separate these clubs. The Red Sox are in a virtual tie with Tampa Bay for last place and the Astros are in fourth place in the West.Houston had dropped seven straight games before scoring 28 runs to sweep a three-game set in Texas this week."The way we came into here, after losing seven in a row, for our guys to respond the way they responded in this three-game series, I'm extremely proud of them," manager Bo Porter said.The Red Sox were losers of seven of eight before winning the final two of a four-game home set with the Chicago White Sox in walk-off fashion.Brock Holt singled in the winning run in Wednesday's 5-4 victory that capped a rally from four runs down in the eighth inning. Mike Carp's pinch-hit RBI single in the 10th inning gave Boston a 4-3 win Thursday."Hopefully it gives us some momentum going into the final series before the break," manager John Farrell said.The Red Sox are using younger players such as Holt, Jackie Bradley Jr., Xander Bogaerts and Mookie Betts, with catcher Christian Vazquez going 0 for 3 in his big-league debut Wednesday."Our young guys are playing pivotal roles as they've been in the mix," Farrell said.Youngsters are also gaining crucial experience for Houston. Rookie Jon Singleton was the hitting star in the sweep of the Rangers, going 6 for 12 with five RBIs.Second baseman Jose Altuve leads the majors with 127 hits, going 5 for 13 in the Texas series.Both teams will start right-handers Friday.Boston's John Lackey (9-6, 3.84 ERA) tries again to notch double-digit wins for the 11th straight year. He gave up five runs over 5 1/3 innings while matching a season high with 11 strikeouts in Saturday's 7-4 loss to Baltimore.Lackey is 1-1 with a 4.86 ERA in three career starts versus the Astros.Houston's Scott Feldman (4-5, 3.86) went 0-2 with a 9.49 ERA in three starts against Boston last year while pitching for Baltimore. Feldman, who has turned in three straight six-inning stints for the Astros, remains wary of the Red Sox."I know they've got a couple of different guys in the lineup, but for the most part the main guys are still there," Feldman told MLB's official website. "I think it's a matter of time before they get hot."Boston won six of seven from Houston last year and has taken 13 of 16 in this series.