CINCINNATI -- Bad defense finally caught up with the Red Sox on Friday night.

The Red Sox fell behind early in a home run derby, but really they lost Friday’s game late on small ball and a breakdown of fundamentals as they fell to the Reds, 5-2, in the opener of a three-game series at Great American Ball Park.

The defense that ranks last in MLB in fielding percentage (.979), errors (57) and unearned runs allowed (48) committed three errors in the bottom of the seventh, as the Reds took advantage to score two unearned insurance runs on the way to just their third win in 10 regular-season tries against the Red Sox in Cincinnati.

Boston fell to 40-36, but is still the first MLB team to win at least 40 of their first 76 games despite making 50 or more errors and allowing at least 40 unearned runs since the 2004 team that managed to right the ship in August and September and shock the world in October.

The Red Sox, winners of eight of their last 10, had their five-game win streak snapped.

The crowd of 37,146 was treated to five solo home runs in the first three innings, before Cincinnati took advantage of TJ Friedl’s sacrifice squeeze bunt that scored both Santiago Espinal and the lumbering Luke Maile from second base.

Cam Booser came on in relief of starter Kutter Crawford, and it was Booser who tried to shovel the ball to catcher Connor Wong. But the ball sailed past Wong and allowed Maile to score for critical insurance and push Cincinnati’s lead to 5-2.

But that’s not what manager Alex Cora or Wong pointed to as much as giving Cincinnati five outs in the seventh inning, as second baseman Enmanuel Valdez allowed leadoff batter Espinal to reach on a throwing error to open the floodgates.

Rafael Devers committed another error in the inning that did not result in a run, but still Crawford (3-7) was charged with five runs (three earned) over his 6 1/3 innings.

“It was an interesting outing for Kutter, right? The homers and the traffic early on, and then after that, he was dialed in and we didn't make a play,” Cora said. “The squeeze is the squeeze, but we opened the door for them and they scored two there. We felt like where we were in the lineup and at-bats wise where we were, we were going to be OK later in the game, but it just didn't happen.”

Jeimer Candelario got the Reds off to a head start against Crawford, who struck out seven and walked two. The designated hitter returned to the starting lineup after a right knee injury on Tuesday in Pittsburgh and belted his 13th homer on a 92 mph four-seamer from Crawford at the knees.

Wong answered in the top of the second when he belted an 80 mph Andrew Abbott curveball to the seats in left for his sixth of the season, extending his hitting streak to 11 games in the process.

Crawford then left a 78 mph sweeper over the middle of the plate to Jonathan India for a first-pitch homer to the seats in left.

The Red Sox tied it up once again when Jarren Durran obliterated an Abbott changeup 401 feet to the seats in right.

Duran became just the fourth Red Sox batter with at least seven homers, 10 triples and 21 doubles in the first 76 games, and the first since Nomar Garciaparra in 2003. Babe Ruth (1918) and Buck Freeman (1903) also turned the trick.

Candelario’s second homer of the night gave Cincinnati its third one-run lead, 3-2, leading off the third. All three Cincinnati homers came on first-pitch swings against Crawford.

“It was kind of like an emotional roller coaster,” Crawford said. “Obviously, gave up the three long balls and a couple of walks in there in that second inning. I was kind of able to kind of dial it in after that third inning and go 6 1/3 [innings].”

The second Candelario homer got the pitcher focused and he retired 11 of his next 12 batters.

“Candelario hitting that ball [410], it’s kind of a punch in the mouth,” Crawford said. “Tried getting ahead first pitch and he jumped all over it, didn’t miss it and put a good swing on it. They didn’t miss the pitches over the heart of the plate.”

The Red Sox struck out 14 times against Cincinnati’s pitching, including 10 against starter and winner Abbott (6-6).