For the reeling Red Sox, who fell to 59-66, this was their fourth loss in a row. Boston is 6-15 in August. They were swept by the Angels at Fenway, where Valentine's team has lost nine of its last 11 games.
"We're playing [bad, bad] baseball," said Alfredo Aceves, who had one of his worst outings of the season to blow the save. "Just come back tomorrow and try and win a game."
A second-inning lead of 6-0 wasn't nearly enough. The Angels roared back with eight in the top of the third.
Boston bounced back to take a 9-8 lead in the sixth, and that wasn't enough, as the Angels tied it against Andrew Bailey in the seventh.
When Jacoby Ellsbury (3-for-6, three RBIs) ripped an RBI single to snap a 9-9 tie in the bottom of the eighth and Dustin Pedroia (four hits, homer, five RBIs) followed with what seemed to be a key insurance RBI single, the Red Sox were just three outs away from victory.
Vernon Wells drilled a one-out solo homer against Aceves in the ninth, and Boston was clinging to an 11-10 lead.
That long ball proved to be controversial, as TV replays showed that it hit the red line and actually didn't go over the Green Monster. However, Valentine didn't challenge it and nobody else on the field seemed to realize it wasn't a home run.
A lot more had to go wrong for the Red Sox for the blast by Wells to have a lasting impact on the game -- and a lot more did go wrong.
The Sox were just one out away from victory when Mike Trout lined a single in front of Cody Ross. That play turned out to be worse when Ross over-ran the ball for an error, allowing Trout to reach second. Torii Hunter followed with a line single to left, and Trout just beat the throw home from Scott Podsednik to tie it.
"I thought it was real close," Red Sox catcher Jarrod Saltalamacchia said. "I thought I had him, but watching the replay, the foot got in before I tagged him."
Mark Trumbo slammed a single up the middle, and the Angels were back on top, 12-11.
But from another deflating blow came a big hit -- a solo shot by Ross that tied it up in the bottom of the ninth.
Unfortunately for the Red Sox, there was still yet another momentum swing to come in this one.
Aceves, who was hit around through a 33-pitch ninth, came back out for the 10th. Kendrys Morales belted the second pitch of the inning over the wall in right, at last putting the Angels ahead for good.
Why did Valentine go back to Aceves for a second inning after he was so shaky in the ninth?
"It was basically the same thing [Angels manager Mike] Scioscia did," Valentine said. "His closer gives up a lead. We had two left-handers in the bullpen and they had a right-handed lineup. We had three innings [of pitching] left, I didn't want to [lose] another inning out. It obviously was the wrong decision."
For good measure, the Angels added an insurance run.
"I missed a couple of pitches, yeah," Aceves said. "It's not [because of] that we lost the game. There were like  runs so it's not that I [made bad pitches] and we lost because of that. It's the entire game."
With another three outs, the Red Sox kept fighting. Pedro Ciriaco smoked a one-out single in the 10th. With the Red Sox down to their last out, Pedroia came through yet again, looping a single into right to make it 14-13.
"It seemed like Pedroia had some kind of joystick on the ball, he got a hit almost every time up," said Angels starter C.J. Wilson. "It was kind of like he knew what was coming."
Up stepped Adrian Gonzalez, who could have given the Red Sox a walk-off win with one swing. But he struck out on three pitches.
"It was a crazy night and you feel like whoever is hitting last is going to win, one of those things," Pedroia said. "I had confidence in our team until we lost. You have to feel that way."
Early on, it seemed like this might wind up being a nice stress-free win for the Sox. For they were able to do something in this one that has been increasingly rare in recent weeks -- play with an early lead.
After a two-out double to center by Pedroia in the bottom of the first, Gonzalez smacked an RBI single up the middle to make it 1-0.
Wilson ran into a much bigger jam in the second. Podsednik and Ellsbury produced RBI singles to make it 3-0. It was Pedroia who came up with the big swing, launching a three-run homer into the Monster seats to give Franklin Morales a 6-0 lead.
It was hard to fathom that the lead could disappear a quickly as it did. But the Angels would send 13 men to the plate during their eight-run top of the third. The inning was a disaster. There were at least three plays the Red Sox could have made outs on, but didn't, making it a six-out inning.
With two outs and the Red Sox still up, 6-2, third baseman Ciriaco committed a fielding error on what would have ended the frame.
It was somewhat surprising that Valentine then lifted Morales and brought on Clayton Mortensen.
"I felt a little surprised because I threw one pitch to make the ground ball, and if the ground balls is out, it gets me out [of the jam]," Morales said. "That's the game. He tried to instead to put the bullpen in that situation."
By the time Mortensen finished the third, the Sox were down, 8-6.
Though losing such a sizable lead had to be deflating, the Red Sox did come back. Ross laced an RBI single to right in the fifth to make it 8-7.
And in the sixth, Mike Aviles tied it back up with a blast over the Monster against Jason Isringhausen. Ciriaco drilled a two-out double against Jordan Walden and Ellsbury put the Red Sox back in front with an RBI double off the Monster.
The theme of the night again was on display, as Boston couldn't hold on. Bailey came on for the seventh and gave up singles to Morales and Erick Aybar. After retiring the next two batters, Bailey gave up a game-tying RBI single to Trout.
As resilient as the Red Sox were in this one, the Angels gave them one counterpunch too many.
Why do the Red Sox seem to be losing all the close games this season?
"I'm not sure," Pedroia said. "We're playing hard. We've just got to find a way to be one run better than them. We haven't done that lately."