The win moves Texas to five games ahead of the LA Angles of Anaheim for first place in the AL West. The Angels defeated the Blue Jays on Tuesday.
"It's easier for a hitter to just be themselves in this lineup," said Beltre. "From top to bottom it's one of the best in baseball."
Derek Holland (15-5) pitched seven innings and gave up one run on two hits with three walks and seven strikeouts to win his fourth straight decision.
Coco Crisp and Michael Taylor each hit solo homers for the Athletics, who have lost three of four. Rich Harden (4-4) dropped his second consecutive start as he was tagged for six runs -- five earned -- on seven hits in just three innings of work.
"He didn't have his best stuff tonight," said Oakland manager Bob Melvin about Harden. "When he missed they hit it and they were able to put some runs on the board quick."
Beltre's three-run home run in the first staked Texas to a 3-0 lead and the Rangers added to their advantage in the second.
Nelson Cruz led off with a double and moved to third on Endy Chavez's groundout. Later in the frame, a wild pitch from Harden scored Cruz for a 4-0 advantage.
The runs continued to come in the third. Hamilton led off with a double and Young followed with an RBI single. Later in the inning, a Mike Napoli single scored Young for a 6-0 lead.
Taylor's first career home run came in the fifth to get the A's on the board.
It was also the first RBI of Taylor's career...Texas has won 12 of the 15 games with Oakland this season...Aside from the two homers, the A's only managed one more hit and three walks and did not get a runner in scoring position. ..Texas shortstop Elvis Andrus went 1-for-5 to extend his hitting streak to 13 games.