But the good news outweighed the bad on this night.
The Angels also lost, keeping the Mariners within one game of the American League West leaders, left-handed starter Horacio Ramirez pitched well, surrendering three unearned runs, and newcomer Rick White pitched well in his Seattle debut, although he absorbed the loss.
"I was happy with the way I threw the ball, but not with the results," White said. "If I can throw like that the rest of year, then more than not there will be good results."
Beltre, regarded as a Gold Glove Award candidate, threw wildly to first baseman Richie Sexson with one out and a runner on first base in the seventh -- a throw so wild that Travis Metcalf scored from first base and the batter, Ian Kinsler, who was credited with a hit on the slow roller to third, wound up at third.
Not for long.
He scored when Gerald Laird somehow got his bat on the ball that was coming directly at his head and succeeded to lay down a suicide squeeze bunt.
"When I picked my leg up to go home, I saw the runner kind of breaking, but I couldn't tell if he was going or faking it," White said. "So then, when I started to throw the ball, I saw him square around to bunt the ball and threw it right at his face -- literally.
"He hit the ball right in front of his face. I don't know how he did it. I really don't."
Said Laird: "I still don't know how I did it. It's either I get my bat on it or I eat out of a straw."
After watching replays of the play later, White said he was even more amazed that Laird was able to pull it off.
"He did a great job of getting that bunt down right there. He hit the ball near his knuckle, right in front of his face," White said.
To have the game-deciding rally fueled by two bad throws from Beltre might be even more surprising than Laird bunting a ball that was about to slam into his face.
The only other time Beltre committed more than one error in a game this season was on July 29 against the Athletics.
"He is so good at third, you very rarely see that," Sexson said. "Everyone is entitled to a bad throw, and unfortunately, they made us pay for it."
Beltre sent word after the game that he did not want to talk to the media.
He no doubt felt responsible for the team's second loss on the six-day-old road trip, and it didn't help that he had a chance to redeem himself in the ninth inning with his bat. He walked to the plate with runners on first and third and one out, but he grounded into an around-the-horn double play, started by Metcalf at third.
It was an appropriate conclusion for the Mariners, who were 2-for-15 with runners in scoring position.
"We got our  hits," manager John McLaren said, "but we didn't hit with men in scoring position."
The Mariners, who reached double digits in hits for the ninth consecutive game, stranded two runners in the third, fourth, fifth and seventh innings, wasting such scoring chances as two on and none out in the fourth and a leadoff double in the sixth. Runs that were there for the taking never scored, and it came back to haunt them.
Ramirez, who changed his mechanics and his success in his previous winning start against the Twins in Minneapolis, pitched even better against the Rangers.
He had a three-run lead and a shutout in the works with two outs in the fifth when Beltre fielded a hot shot hit by Metcalf. The tough part of the play was gloving the tricky hop, something Beltre did superbly.
But Beltre's throw to first base was high and pulled Sexson off the bag. After catching the ball, Sexson reached back and tagged the runner as he approached the base.
"I hit him on the chest, but [first-base umpire Jim Wolf] said his foot beat the tag," Sexson said. "I haven't seen the replays, so I don't know for sure. But I thought I got him."
Beltre was charged with his 14th error of the season, and Ramirez had to keep pitching.
And one more pitch was too many as the first one to Kinsler became a souvenir for a fan sitting in the left-field bleachers. Kinsler hit his 16th home run of the season and the game was tied at 3.
"I cut a changeup that was supposed to be away and it moved to the middle of the plate," he said. "It [stinks], because Beltre has been playing unbelievable defense, and I wished I had been able to pick him up. I should have made a better pitch in that situation."
This definitely was a case of a pitcher throwing one bad pitch in a game.
Ramirez ended up going 5 2/3 innings and getting a big pat on the back from McLaren.
"I thought Ramirez threw the ball well," McLaren said. "He gave us a chance to win the game."
McLaren also lauded White, who joined the team from Triple-A Tacoma on Friday, three weeks after being signed to a Minor League contract. He pitched earlier this season for the Astros.
"I thought he did a great job, and I think he is going to help us a lot," McLaren said. "He has a nice presence on the mound, has good velocity. I liked what I saw out of him."