After Ben Zobrist took a full-count pitch, a breaking ball that appeared to be low and outside, he started toward first base and even Nathan appeared to anticipate a ball being called. But home plate umpire Marty Foster then called strike three, though he later admitted he was wrong.
"I saw the pitch and of course don't have the chance to do it again," Foster told a pool reporter after the game. "But had I had a chance to do it again, I wouldn't call that pitch a strike."
Zobrist put both hands on his helmet and took it off in disbelief. Manager Joe Maddon argued with Foster and the other umpires for several minutes after the game ended.
Soon after that Maddon tweeted, "That can't happen in a major league game."
Foster said Maddon was very professional and never violent.
"He was frustrated and I understand," Foster said. "He acted probably the best he can under that situation."
Crew chief Tim Welke indicated that he didn't foresee a scenario where Maddon would be disciplined.
Pierzynski, the Rangers catcher, said he heard the umpire call strike three, and went out to congratulate Nathan.
When asked if he had seen a replay of the final pitch, Rangers manager Ron Washington said he wasn't interested.
Maddon said he "saw it clearly" when it happened, but looked at a replay afterward "to reaffirm what I'd seen. Again, it just can't happen in a Major League Baseball game."
Nathan gave up a run in the ninth, and there was still a runner on base when the game ended and he became the 24th major leaguer with 300 saves.
"Fortunately I got a decent call there at the end. I've seen plenty go the other way," Nathan said. "The umpires have a tough job too. He's back there for three hours, seeing a lot of pitches. I've seen plenty of close calls go against us.
"I threw the pitch where I wanted to. He didn't offer like I thought he was going to. It's pretty safe to say we got a very fortunate call there but we'll take it."
After Pierzynski's first homer for Texas, a two-out solo shot in the fourth that made it 2-1, Moreland pulled a 428-foot shot deep into the Texas bullpen in right-center field.
Alexi Ogando (2-0) allowed only one run on three hits but needed 89 pitches to get through 5 1-3 innings. The right-hander walked three and struck out two five days after getting a career-high 10 strikeouts in 6 1-3 innings at Houston.
Hellickson (0-1), who turned 26, gave up three runs and five hits over five innings. He needed 30 pitches to get out of the first, including a nine-pitch leadoff walk by Ian Kinsler, and threw 98 pitches overall.
Elvis Andrus, in a 2-for-18 slide before singling in the fifth, added a two-run single in the Rangers seventh for a 5-1 lead.
Pierzynski became the seventh different player to homer for the Rangers in their seven games. Moreland then hit his second homer of the season, part of his three hits against the Rays after going 2 for 21 the first six games.
Even though Kinsler got caught stealing in the first, Texas went up 1-0 when Lance Berkman scored from first base on Adrian Beltre's two-out bloop double. Left fielder Sam Fuld made a diving attempt to catch the ball, which instead went under his glove and rolled behind him.
Tampa Bay got even in the second. Evan Longoria drew a leadoff walk in the second, and scored when second baseman Kinsler made a throwing error when trying to complete a double play.
Yunel Escobar reached second base on that misplay. But Escobar didn't score in part because of a running, over-the-shoulder catch by right fielder Nelson Cruz only steps from the wall for the second out, a play that had third-base coach Tom Foley shaking his head in disbelief.
Longoria was 3 for 3, all singles, including one in the eighth when the Rays loaded the bases and scored twice. He is hitting .417 (10 of 24) with only singles and is longer into any previous season without a home run.
Ogando, an All-Star starter in 2011 before working out of the bullpen last season, got into the sixth before walking Zobrist and giving up another single to Longoria.
Joe Ortiz, the 22-year-old rookie lefty who is only 5-foot-7, got out of that jam with a pair of grounders and then worked a 1-2-3 seventh.
Hellickson pitched on his birthday for the second year in a row. On his 25th birthday, his 2012 debut, he pitched 8 2-3 scoreless innings in the Rays' 3-0 win over the New York Yankees.
NOTES: Beltre, the Gold Glove-winning third baseman, started the game with a standout play. He was up on the grass when Desmond Jennings hit a shot down the line. Beltre dove at an angle going backward to make a backhanded stab, then got up and threw out the leadoff hitter. ... Tampa Bay's first error of the season came in the second inning when 2B Zobrist was unable to snag Pierzynski's grounder. ... Nick Tepesch, a 24-year-old right-hander, will be called up for the Rangers to start in his major league debut Tuesday.