Nathan allowed the first runs against him in almost six weeks while throwing 32 pitches in the ninth, but finally subdued the Rockies by striking out Jason Giambi to end the game.
Giambi represented the tying run. The Rangers were fortunate that he didn't represent the go-ahead run with one out and runners at second and third.
"It got interesting," Nathan said. "It's a credit to their lineup. They've got a lineup that can put up runs in a hurry if you're not sharp. I was just trying to make pitches. It was hot out there. It was steaming, I had a good lather going. But I wasn't tired, I still felt good."
Nathan, asked to protect a 4-0 lead, did not get credit for an official save, but he did preserve Harrison's 10th win. Harrison pitched five scoreless innings before leaving with tightness in his lower back but is not expected to miss his next start. He has now won six straight decisions and is 10-3 with a 3.24 ERA on the season.
"He was outstanding," Rangers manager Ron Washington said. "He didn't want to come out, but we weren't taking any chances."
Robbie Ross, Tanner Scheppers and Mike Adams all threw scoreless innings after Harrison left before Washington turned the game over to Nathan in the ninth.
"That was huge," Harrison said. "Robbie, Schepp, Adams, and Nathan, they've been doing a really good job lately and they did it again tonight. I want to mention Martin, too."
Martin was worth mentioning. The Rangers were 3-for-16 on the night batting with runners in scoring position and Martin had two of those three hits. He had an RBI double in the second and Elvis Andrus followed with another double to give the Rangers a 2-0 lead. Martin added a two-run triple with two outs in the third.
"We knew the kid could swing the bat," Washington said. "He picked us up big time tonight. Two two-out hits. They were huge."
Martin and Andrus, who finished the night with three hits, provided almost all of the offense until the ninth inning. Then the Rockies came alive.
Jonathan Herrera led off with a single and Dexter Fowler drew a walk after fouling off three full-count pitches. Nathan then hit Eric Young with a 1-2 pitch to load the bases.
"I threw it right at his elbow and he didn't move," Nathan said. "The last thing you want to do with a 4-0 lead is load the bases with nobody outs."
Marco Scutaro followed with a sharp single to left, driving home one run and leaving the bases loaded. It was the first run allowed by Nathan since May 13. That brought up Carlos Gonzalez, who jumped on a first-pitch curve and launched it to deep left-center. But Josh Hamilton, playing left field, was able to run it down on the warning track in front of the Rockies' bullpen.
"I hit it pretty good, but I hit it to the toughest part of the place." Gonzalez said. "I was just hoping that ball was a double, but [Hamilton] made a great catch."
The Rockies still had runners at first and second with Giambi at the plate. On an 0-1 pitch, Nathan bounced a curve in the dirt that catcher Mike Napoli blocked. The ball rolled to his right, probably far enough for both runners to advance. Scutaro certainly thought so, but Young wasn't so sure.
Young started for third but thought better of it and went back to second. Scutaro went for second and didn't stop until it was too late. He was too far toward the base and Young was already there. Napoli went at Scutaro as he headed back to first. Napoli flipped the ball to Michael Young as Eric Young went for third. Michael Young didn't care, he focused on getting Scutaro.
"An out somewhere was all we were thinking about there," Michael Young said.
Young chased Scutaro toward second and then threw to Andrus covering. But Scutaro slid into second under the tag and was called safe by second-base umpire D.J. Reyburn. Then Scutaro came off the bag and was tagged out by Andrus.
"For some reason I just bounced," Scutaro said. "I don't know if Andrus pushed me or I hit the bag and bounced back. I don't know."
"I have no clue what happened," Andrus said. "But as soon as I saw he was called safe, he fell off the bag and I just tried to tag him."
Regardless of what happened, the play ended up killing the rally and Nathan struck out Giambi to end the game.
"They threw up some good at-bats," Michael Young said. "Joe has been pitching great and they had some good at-bats. Fortunately, we were able to catch a break."