Feldman scattered five hits over six innings, and the Rangers beat the Oakland Athletics 5-2 to complete a doubleheader sweep on Friday night.
In the first game, Andruw Jones hit a tiebreaking two-run homer in the eighth to send Texas to a 6-3 victory.
Feldman (4-0) gave up two runs, struck out two and walked three to help the Rangers win for the sixth time in eight games. He allowed four baserunners in the first inning, but gave up only one run before settling down.
"I thought he did an excellent job to hang in there the way he did," Rangers manager Ron Washington said.
Feldman has pitched at least five innings in each of his seven starts since being inserted into the rotation on April 25 when Kris Benson went to the disabled list because of right elbow tendinitis. Feldman has a 2.59 ERA this season since coming out of the bullpen.
"I started behind in the count on too many guys, and that will drive your pitch count up," Feldman said of his early struggles. "But anytime your team wins, you've got to be grateful."
Texas (29-19) has matched the 1996 team for the second-best start in club history.
The A's had won three of their previous four, but strong Rangers pitching stopped any momentum Oakland carried into the series.
"It's a letdown," A's manager Bob Geren said. "We've been playing pretty good. That puts a damper on things."
In the second game, Ryan Sweeney's RBI double gave the A's the lead in the first inning, but the Rangers jumped on right-hander Edgar Gonzalez (0-1) for four runs in the bottom half. Josh Hamilton and Hank Blalock had RBI doubles and Taylor Teagarden added a two-run single.
Geren ordered Gonzalez to intentionally walk left-handed batter Chris Davis to pitch to the righty swinging Teagarden, but the move backfired when Gonzalez hung a slider. Davis went 0-for-7 with six strikeouts in the doubleheader, upping his majors-leading total to 77 Ks.
"You've got a guy [Davis] who has 12 home runs, two in the last week, against a guy who doesn't play that often," Geren said. "If you can face the next guy, you do it."
Gonzalez, making his second start of the season, gave up five runs and eight hits in five-plus innings, striking out four and walking three.
With the score 3-all in the opener, Santiago Casilla (1-2) walked Hamilton leading off the eighth. Jones followed, pulling a 2-1 fastball off the screen on the left-field pole for his fifth homer.
Nelson Cruz, who had three RBIs, followed Jones with his 13th homer.
Wilson (2-2) pitched a perfect eighth and Frank Francisco worked the ninth for his 11th save in as many chances.
Oakland got another strong performance from rookie left-hander Josh Outman, who struck out a career-high nine and allowed three runs and three hits in 6 2/3 innings.
Outman has given up five earned runs and 13 hits in his last 26 1/3 innings over four starts.
Texas was 31-17 after 48 games in 1998 for the best start in club history. ...The first game was the makeup of an April 29 rainout. ... The A's have been swept in each of their last four doubleheaders. ... Rangers first-game starter Tommy Hunter, called up from Triple-A Oklahoma City earlier Friday for his first big league appearance this season, allowed three runs and seven hits in 5 1-3 innings. Hunter was returned to Oklahoma City after the first game, and right-hander Guillermo Moscoso was called up from Double-A Frisco to replace Hunter. ... Oakland's Bobby Crosby pinch-hit for DH Jack Cust in the third inning of the first game. Cust, who flied out in the first, has been slowed by lower back spasms. Cust wasn't available for the second game. Cust and Buck are day to day.