CHICAGO -- So maybe the Astros aren’t baseball’s most infallible team. It seemed that way just a few days ago when they dropped 23 runs on the Orioles for their eighth win in a row -- all of which came on the heels of their blockbuster trade to acquire Zack Greinke from the D-backs. Life was good in Astroland.

The Astros are still among American League royalty with a 78-43 record and a stacked lineup and rotation, but even supremacy can have a few bad days. That’s the case for Houston, which has lost three of four games since Saturday’s romp in Baltimore, including a 13-9 slugfest to the White Sox in Wednesday’s series finale at Guaranteed Rate Field.

• Box score

Despite bashing out 15 hits, including two homers by Yuli Gurriel and a two-run game-tying homer by José Altuve in the eighth inning, the Astros couldn’t keep up with the White Sox, who got a two-out, two-strike grand slam in the eighth off the bat of James McCann against All-Star reliever Ryan Pressly to break a 9-9 tie.

“I left the pitch in the middle of the plate and he capitalized on a mistake,” said Pressly, who hung an 0-2 slider. “Tip your hat to him.”

The White Sox took two of three from Houston and won the season series over the Astros, who lost consecutive games for the first time in a month. The Astros made two errors in the second inning that led to four unearned runs, including Wade Miley’s ill-advised glove flip to the plate on a squeeze bunt that sailed to the backstop and allowed two to score. Miley later called the play “stupid.”

“We were pretty sloppy today early in the game and made some bad decisions on defense,” Astros manager AJ Hinch said. “We just couldn’t keep them from scoring. They scored six of their eight at-bats. They put runs on the board. They did a really good job of continuing to attack us offensively, but the big swing with the bases loaded…”

Gurriel (3-for-4), Michael Brantley (4-for-5), Altuve (3-for-5) and Alex Bregman (2-for-5, three RBIs) spearheaded the Astros’ 15-hit attack. Yet Houston fell to 48-1 in the last five seasons when banging out at least 15 hits.

“We had a couple of opportunities,” Hinch said. “Yuli hit the one bullet to center that could have changed things [with bases loaded to end the eighth], but at the end of the day we got outplayed on both sides of the ball.”

Here are three takeaways from Houston’s first series loss since June 25-27 against the Pirates:

1) Bullpen carrying the freight

Monday’s rainout forced the Astros to play three games in a span of 24 hours on Tuesday and Wednesday, and when starting pitcher Gerrit Cole was scratched prior to Game 2 on Tuesday and Wade Miley lasted 3 1/3innings on Wednesday, the bullpen was faced with a heavy load. Houston relievers allowed six runs in 4 2/3 innings, including home runs given up by the two steadiest bullpen hands: Will Harris and Pressly.

The Astros called up rookie Cy Sneed prior to Wednesday’s game to simply have a fresh arm, sending down Joe Biagini, who threw 46 pitches in three innings in Tuesday’s Game 2 loss. Houston is at the beginning of a span in which it plays 17 games in 17 days, so bullpen usage will continue to be a topic of concern moving forward. Brad Peacock could return from the injured list in the next week, but the Astros might have to shuffle a few more relievers between Houston and Triple-A Round Rock before rosters expand Sept. 1.

2) White Sox work around Alvarez

It was clear the White Sox didn’t want Yordan Alvarez -- the June and July American League Rookie of the Month -- to beat them. The lefty slugger went 1-for-11 with one RBI and one walk in the three-game series, including two intentional walks.

The White Sox intentionally walked him in Game 2 on Tuesday and got Gurriel to hit into an inning-ending double play, and Carlos Correa hit behind Alvarez on Wednesday, going 0-for-2 with three walks. It will be interesting to see how other teams approach Alvarez going forward and how Hinch manages his lineup in terms of which players hit behind him for protection.

3) Gurriel remains hot

Gurriel is making a bid for his second consecutive American League Player of the Month honors. He bashed solo homers in the second and sixth innings on Wednesday and added a bases-loaded RBI single in the seventh. He came up again with the bases loaded in the eighth and hit a line drive to center field for an out.

Gurriel is batting .391 with 20 homers and 52 RBIs in his last 40 games -- a remarkable stretch during which he’s been the most consistent run-producer in Houston’s deep lineup. His 84 RBIs lead the team and are one shy of his career high from a year ago. He has a chance for 100 RBIs by the end of the month.