CHICAGO -- For James Paxton, Saturday started with the same type of dominance he has displayed throughout this comeback season. Six up, six down went the Cubs, as Paxton needed only 22 pitches to breeze through the first two innings.

This is what made the lefty’s third-inning implosion unexpected in a 10-4 defeat to the Cubs at Wrigley Field that halted the Red Sox’s winning streak at six games.

In that fateful frame, which saw the Cubs score six times, it started with Paxton doing some self-inflicted damage by going walk, hit by pitch, walk to the 7-8-9 hitters.

Why the dramatic switch from one inning to the next?

“Just got myself into some bad counts and left some balls over the middle of the plate, and they did damage,” Paxton said. “Just kind of lost the handle and wasn't able to find it.”

Paxton matched his season high for walks with three, the latter occasion coming in his only other shaky outing on May 24 in Anaheim. It was wildly unexpected he would walk three in the same inning.

There will be some film work in the next few days, Paxton acknowledged, prior to his outing against the Mets on Friday at Fenway. But on the spot, he wasn’t able to diagnose what ailed him.

“I just didn't feel quite right,” Paxton said. “If I had known exactly what was going on, I would have fixed it in the moment or at least tried to. But I lost my handle and they did their damage.”

There were also two defensive miscues that preceded the game-breaking blow: a grand slam by the red-hot Cody Bellinger.

On a crisp grounder by Nico Hoerner, Kiké Hernández deftly stabbed it on the dive and tried to gather himself for what would have been a forceout at second. But Hernández lost the ball on the transfer and everyone was safe with a run scoring.

Then came the next mishap. Seiya Suzuki hit a grounder to third, and Rafael Devers stepped on the bag for the long-awaited first out of the inning and should have had a double play, only for his throw home to sail high and wide on catcher Connor Wong, who didn’t catch it cleanly.

Though the error was charged to Devers, Wong took the blame for it.

“Ideally, that throw is on the inside lane, but it wasn't,” Wong said. “I don’t think that's an excuse for not catching the ball. It really wasn't that bad of a throw. Just catch it and get him out.”

Bellinger did not let his golden opportunity go to waste, destroying a fastball on the upper, inner portion of the strike zone.

“The first pitch he swung and missed,” said Red Sox manager Alex Cora. “Then he got to a pitch, we tried to go up and probably we wanted it higher than that, and he put a good swing on it.”

From there, the Red Sox never put much of a dent into Chicago’s commanding lead.

In one start, Paxton’s ERA jumped from 2.73 to 3.51. But given how consistent he has been, the isolated mishap was really nothing for anyone to fret about.

“It’s not my first bad game and it won’t be my last,” said Paxton. “You’re going to have these starts during the season and it’s all about what you do to get back to doing what you want to do out there. We all fail at times and it’s more about how you deal with failure than the failure itself.”

Similarly, the Red Sox, who have been on a roll, aren’t going to get discouraged by a bad afternoon of baseball. Not when they can win the rubber match on Sunday.

“Similar to the Anaheim outing, [Paxton] lost command, and then the pitch up in the zone to Bellinger -- and right now he’s swinging the bat well. He hit it out of the ballpark,” said Cora. “If we still make that play at the plate, it might be a different story. It’s two outs, only one run, we’re one pitch away from getting out of that inning.

“But it’s going to happen. Connor has been one of the best defensive catchers in the big leagues, but he’s going to make mistakes like the rest of us. So we’ve just got to be ready for tomorrow.”