BOSTON -- The Chicago Cubs were on the verge of taking advantage of mistakes made by the opposition until they made a trio of their own during a four-run eighth inning by the Boston Red Sox on Sunday night. It was an ugly frame for the World Champions, who lost 6-2 in the finale of their road trip.

"Not covering first base really opened everything up for them," manager Joe Maddon said of a key play in the inning. "I think he [Koji Uehara] thought [Anthony] Rizzo was closer to the bag."

With the score tied 2-2, Uehara was late to first base on Marco Hernandez's ground ball to open the inning. The 42-year-old right-hander was pitching in back-to-back contests for the second time this month, and it would be the softest contact he gave up, as the next two batters singled to load the bases. Maddon then pulled Uehara in favor of Pedro Strop.

"I got there as quick as I could, the runner was just faster," Uehara said after the game.

Strop got Mookie Betts to strike out -- not an easy task -- for out No. 1 before throwing a wild pitch to Hanley Ramirez, which plated the go-ahead run. He induced two more ground balls, but shortstop Addison Russell threw the latter one in the dirt to first base, allowing two more runs to score.

Game. Set. Match.

"I thought Strop did a great job," Maddon said. "Wild pitch -- other than that, he did a really nice job in there."

The inning -- and game -- was somewhat indicative of the Cubs' play all month: a little inconsistent in areas where the Cubs usually strive – pitching and defense. But this isn’t 2016, and things haven't come as easy so far. Of course, there's a fine line to winning and losing, as Cubs left fielder Jon Jay scored from second base on a wild pitch to tie the game just one inning earlier.

If the Cubs would have gone on to win, the Red Sox are the ones with egg on their face and the Cubs are 14-10 this month instead of 13-11. In fact, Maddon thinks the game came down to one play -- when Hernandez barely touched first base before Uehara could. A review said only that the called stood, not that it was confirmed. It was that close, and so was the game until the eighth inning.

"If he [Uehara] covers first base, he has two nice outings in a row," Maddon said.