Harden threw 111 pitches in his five innings, and the Rays' hitters fouled off more than 20 of his pitches, including a 15-pitch at-bat by shortstop Reid Brignac in the fourth inning.
"That's something they were doing the whole day, not just to me but the other pitchers, too," Harden said. "I had one 15 pitch at-bat, and that cost me. I still felt really strong. I wanted to go back out. I felt good. Heat wasn't a factor. They were just fouling pitches off, fouling pitches off. That's the way it goes."
The Rays tagged Harden for three runs spanning the second and third innings on homers. Designated hitter John Jaso belted a two-run homer in the third, and first baseman Carlos Pena added a solo shot an inning later as Tampa Bay jumped out to an early 3-1 lead.
"I felt good," Harden said. "Really, that was it. I made a couple of mistakes, like the changeup to Pena. Really, other than that, I felt good about how I threw today and how I felt. I just didn't get it done."
The Rangers had taken the lead in the second when catcher Matt Treanor belted a 3-2 fastball over the left-field wall. He added another solo shot in the ninth. It was the first multihomer game of Treanor's career. His five home runs on the season are also a career high.
"He's been swinging the bat very well," Washington said. "He's just putting some stuff together. He looked good up there today. ... I'm very happy for him."
Harden exited with the Rangers trailing, 4-2, as he gave up an RBI single to Evan Longoria in his final inning. It marked the eighth time in his 12 starts that Harden has received three runs of support or fewer.
"When he left the game, we were still in the game," Washington said. "But he's got to figure out a way to get us deeper in the ballgame. He's just got to keep working at it. He knows and we know that he's got to get better."
Despite Harden leaving with the game still within their grasp, the Rangers were never able to pick up the clutch hit to put them over the top. Texas cut the deficit to one run on two separate occasions but couldn't grab another base hit to swing the advantage in their favor.
"Offensively, we had a pretty decent approach," third baseman Michael Young said. "They just kept pushing us offensively. It just made for a real long afternoon."
Harden placed the blame for the loss on himself, not the Rangers' offense that had scored 15 runs over the first two games of the series.
"It's still not going the way I want it to go right now," Harden said. "I feel great. That's the frustrating part, that I do feel really good. I just hope to turn this around. Gotta work on it."
Despite the Rangers having a wealth of pitching waiting in the wings in the farm system, along with the injured Derek Holland returning soon, Harden isn't focusing on whether his starting position is in jeopardy.
"I don't think about that," Harden said. "No matter what the scenario is, I still have to pitch well."