Cruz, who is among 14 players facing a possible suspension as part of Major League Baseball's Biogenesis investigation, hit his 26th home run of the season in the second inning to turn the momentum in the opener of a critical division series. Profar put the Rangers ahead 6-2 with his fourth homer in the fourth.
The Rangers, who were six games behind Oakland in the AL West earlier this week, are only 2 1/2 games back.
"The offense just woke up at the right time," Cruz said. "We've been quiet for a while. It's a good time to wake up."
Brandon Moss' two-run double in the first gave the A's the lead, but Tommy Milone struggled on the mound and Oakland stranded 10 runners to lose its third in a row. Milone (9-9) allowed six runs -- including both homers -- and nine hits in 3 2/3 innings.
"That was pretty terrible," Milone said. "They did a good job of hitting my mistakes. I didn't make that big pitch."
After going 32 days without gaining ground on Oakland, the Rangers are making up for lost time. Texas has gained 3 1/2 games in the division in four days.
Rangers manager Ron Washington also matched Bobby Valentine for the most wins by a manager in franchise history. Washington, the longtime A's third-base coach, is 581-501 in seven seasons.
All the good vibes still come in the shadow of a looming investigation that could deliver a major setback.
MLB is prepared to issue two simultaneous announcements no later than Monday, a person familiar with the process told The Associated Press earlier this week. One would list players who accept suspensions; the other would name those disciplined without deals, but who could challenge penalties before an arbitrator.
Most players face 50-game suspensions for their links to the now-closed Florida anti-aging clinic.
Barring a rainout this weekend, the Rangers would have exactly 50 games remaining as they head into play Monday at the Los Angeles Angels. If Cruz files a grievance, as a first offender, the penalty would be delayed until after a decision by arbitrator Fredric Horowitz. But the lengthy legal process likely would risk his eligibility for the playoffs and the start of next season.
Cruz said he hasn't made any decision about a possible appeal.
Cruz cracked the tying homer just over the 400-foot marker in straightaway center in the second. As he trotted around the bases, the announced sellout crowd of 35,067 smothered him with boos -- and each time he was announced at the plate.
"Very impressive. He's been swinging the bat like that all year," Washington said. "It seems like every time we need something, he comes through for us. He's been able to separate, man."
Jason Frasor (2-2) tossed 1 1/3 scoreless innings of relief for the win. And A.J. Pierzynski drove in three runs, including a two-run single off Dan Otero in the seventh that put the Rangers ahead 8-3.
Alexi Ogando labored through four innings but allowed just three runs and four hits while walking five. He threw 92 pitches, including 60 in the first two innings, doing just enough to keep the Rangers in control.
Every A's attempt to rally came up at least one hit short. Josh Donaldson grounded into a double play with two runners on in the third, and pinch-hitter Alberto Callaspo lined out to center with the bases loaded to end the fifth.
"We just got a little stagnant. We got baserunners, but we didn't get the hits," A's manager Bob Melvin said.
Cruz handed the A's a run when Coco Crisp's fly ball bounced off the heel of his glove near the wall in right for an RBI double that sliced Texas' lead to 6-3. Martin replaced Cruz, who has been playing with a bruised left quadriceps, in right field to start the bottom of the eighth.
Texas also won five in a row from June 19-23. ... Rangers SS Elvis Andrus extended his hitting streak to 15 games with a single in the third inning. ... A's opening day starter Brett Anderson, recovering from a stress fracture in his right foot, threw about 55 pitches against live hitters. The team will see how Anderson feels Saturday before deciding on his next step, which could be a rehab assignment. ... Jarrod Parker (6-6, 4.07) pitches for the A's against Rangers righty Matt Garza (1-0, 1.88 ERA) on Saturday.
Copyright by STATS LLC and The Associated Press
OAKLAND, CA - AUGUST 02: Tommy Milone #57 of the Oakland Athletics pitches against the Texas Rangers at O.co...