CHICAGO – The Twins' feared flaws hadn't erupted in the first four games of 2017, but that doesn't mean they disappeared entirely. Now, only their winning streak has.

Remember how frustrating Twins starting pitchers could be last year, and how sloppy the defense often was behind them? If those memories were erased by a 4-0 record, they came flooding back Saturday, when Adalberto Mejia lasted only 10 batters in his first major league start, and Miguel Sano committed his first two errors of the season.

The White Sox took advantage of the mistakes early on, clubbed a couple of homers later, and ended the Twins' nothing-but-winning week with a 6-2 loss.

"We talked about having some pretty clean games in the first four," Twins manager Paul Molitor said. "Today was a different story."

Partly it was due to conditions: The game was played in a sneaky-strong and swirling wind that was responsible for two catchable pop-ups falling to the ground. But the wind can't be blamed for Sano's shaky defense, nor Mejia's failure to finish off hitters.

And the biggest gaffe turned a White Sox blunder into a setback for the Twins. Avisail Garcia, who finished the day just a double short of a cycle, was caught breaking for the plate in a squeeze play gone awry during the second inning. Catcher Jason Castro backed him up toward third then threw the ball to Sano, who made a major miscalculation.

"You could tell right away, he thought he would be able to catch [Garcia]," Molitor said. "I don't mind running a guy towards home. If you execute on one throw, you're going to be fine. But but he realized too late he wasn't going to catch him, and he tried to get rid of the ball too quickly."

Sano tried to shovel the ball back to Castro but bounced his toss off Garcia's shoulder, enabling him to cross the plate.

Garcia is faster than you thought, isn't he, Miguel? "Yeah, he is," Sano said, "but I'm still supposed to get an out."

So is Mejia, and that didn't go as well as planned, either. The 23-year-old lefthander tried to put aside the emotions of his first start, but he couldn't do the same with Chicago third baseman Todd Frazier, who led off the second inning by fouling off eight consecutive 3-2 pitches. The 14-pitch at-bat — one of only five that long against the Twins in the past seven years — ended in a walk, and Frazier scored when Garcia scorched a pitch to the wall in right-center, just out of Byron Buxton's reach.

"You could see him getting frustrated because he was making good pitches and [Frazier] was finding ways to stay alive," Molitor said. "But that's the nature of the game up here — these guys are going to grind. You take a breath and go on to the next guy."

After the botched rundown made it 3-0, Mejia got two quick outs, but he then walked Jacob May and hit Tyler Saladino with his 40th pitch of the inning.

"It got away from him a little bit," Molitor said. "I watched the pitch count climb there in the second inning. I was hoping he could get us off the field, but 40 pitches in one inning, it's not usually a good sign."

Jason Castro's first home run with the Twins, a two-run shot in the sixth, cut the deficit to 3-2, but Chicago answered in the bottom of the inning. Reliever Justin Haley, who had retired 10 of the first 12 hitters he faced, gave up a one-out single to Frazier before Garcia launched a homer that bounced off the back wall behind the center-field fence. Geovany Soto blasted Haley's next pitch into the left-field seats, and the Twins' streak was officially doomed.

"We made some mistakes," Molitor said, "and they made us pay."