Saunders, who hadn't started since Sept. 18 because of a kidney stone, allowed just two hits and no walks in his final regular-season start. Saunders is scheduled to pitch against the Red Sox in Game 3 of the Division Series on Sunday at Fenway Park.
"It's a confidence booster," Saunders said. "In my mind, I don't want to go into the playoffs giving up runs or working on stuff. I think this a great outing for me and for the team to put us at 100 wins."
It was quite a performance from Saunders, who called passing a kidney stone Wednesday the "worst experience" of his life. He lost nearly eight pounds in the process, but said that the rest his arm received as a result helped him Sunday.
"It's almost like half a blessing in disguise because my body feels fresh and I lost a little bit of weight and my arm feels great right now," Saunders said. "But I wish that on nobody."
Saunders, who finished the season with a 17-7 record and a 3.41 ERA, kept the Rangers off-balance with his curveball and allowed just one extra-base hit all day. The two hits he allowed made up the least he allowed all season.
"It's probably the best stuff we've seen from Joe in probably his last seven or eight starts, and that's exciting because the layoff definitely helped him," Angels manager Mike Scioscia said. "I don't think we recommend anyone getting kidney stones, but he came back fresher and stronger and it showed today."
Saunders was aided offensively by catcher Mike Napoli, who went 3-for-3 with a home run and drove in four runs.
Napoli opened the scoring on an RBI double in the second before hitting his 20th home run of the season in the fifth inning -- much to the delight of the crowd of 43,761.
The home run came on the first pitch he saw from Rangers starter Kevin Millwood, who allowed five runs over six innings to pick up the loss. Napoli became just the fourth catcher in the Majors to hit 20 home runs with a high drive that he wasn't sure was going to be a home run.
"I knew I hit it OK and kind of high, but I wasn't sure," Napoli said of his home run. "I was talking to it a little bit as I went down the line. But I put a good swing on it, and it happened to go."
Napoli wasn't done, though, as he hit two-run double in the sixth inning after Gary Matthews Jr. connected with a run-scoring single.
Matthews also had a big day at the plate, as the switch-hitter went 3-for-4 with three runs scored against his former team.
The Angels added two more runs in the eighth on a sacrifice fly by Reggie Willits and a bases-loaded walk by Kendry Morales.
The 100th win broke the old club record of 99 wins set by the 2002 team that eventually won the World Series. The Angels became the first team to win 100 games since the '05 Cardinals and the first American League team to do it since the Yankees won 101 games in '04.
The Angels also broke a club record by winning the division by 21 games while becoming the first team since the 1999 Indians to win a division by at least 20 games.
"It's a nice milestone for how hard these guys have worked since Day 1 in Spring Training," Scioscia said. "But now, we'll get ready for Wednesday."