ARLINGTON -- The Rangers head into the final week before the All-Star break with a 3 1/2-game cushion on the Los Angeles Angels in the American League West.

That lead is going to be more difficult to keep if the Rangers don't figure out a way to get Scott Feldman back to the pitcher he was when he came out of nowhere to win 17 games last season.

Feldman, who has yet to get on the right track this season, found no room for error in a 5-3 loss to the Chicago White Sox on Sunday night.

Twice the Rangers staked him to a lead against the always tough Mark Buehrle, who once threw a no-hitter against Texas, and twice Feldman spit the lead up.

The Rangers never recovered after losing a 3-2 lead in the top of the sixth. Feldman went to the mound with the momentum of Julio Borbon's third home run of the season, but allowed back-to-back doubles to Paul Konerko and Carlos Quentin to even the score.

Quentin went to third on a groundout to second base by Mark Kotsay, and third baseman Michael Young backhanded a sharply hit ball by A.J. Pierzynski. With the infield playing in, Young was able to hold Quentin at third and get the out at first.

But Feldman didn't take advantage of the reprieve. White Sox shortstop Alexei Ramirez drilled a 1-0 sinker just over the wall in left field for the ultimate two-run lead.

"That home run he hit, I was trying to go sinker down and away and it just kind of came back over the plate," Feldman said. "It sort of just went right into his swing, and he was able to hit it out."

Ramirez's home run sucked the life out of Texas' bats. Three Chicago pitchers -- Buehrle and relievers J.J. Putz and Matt Thornton -- combined to retire 14 of the final 15 batters they faced.

"Our guys gave me the lead two different times and I let them right back in the game both times," Feldman said. "With Buehrle throwing the way he was throwing over there, you can't do that. It pretty much sums it up."

The frustrating part of Feldman's night is that most of his final numbers pretty much matched up with what he did when he went 17-8 last season. He had 10 ground-ball outs to three fly-ball outs, a ratio he'll take every night he pitches. He was economical with his pitches, using only 83 in his six frames for an average of 13.8 per inning.

But he made one mistake to Ramirez -- Feldman was sixth in the AL in home runs allowed per nine innings -- and it cost him the game.

"I was getting ground balls and I felt like I could get a ground ball there in the sixth with Ramirez," Feldman said, "and it just kind of came back over the plate."

There are other areas where Feldman is slumping. He took over the AL lead in hits allowed from former teammate Kevin Millwood, having allowed 132 hits in 101 1/3 innings. He was 11th in the AL with a .245 opponents batting average last season, but opponents are now batting .314 against him.

That means Feldman has trouble working around mistakes. Young booted a ground ball in the top of the second, and Kotsay followed with a double down the right-field line to give the White Sox the first run of the game.

Feldman took a 2-1 lead into the fourth inning after Josh Hamilton's two-run homer -- which extended his home hitting streak to a franchise-record 24 games -- in the third and walked Ramirez on four pitches. He later scored on Dayan Viciedo's groundout to shortstop to tie the game at 2.

And there's this -- Feldman now has accumulated eight losses, and he came into Sunday getting 6.14 runs per start from his offense.

It all adds up to a ton of frustration for Feldman, who signed a contract extension in the offseason. And he admitted as much in the clubhouse after the gears to the Rangers' ninth-inning rally never got grinding.

"I'm trying not to get to frustrated, but obviously I expect to do better than this," Feldman said. "I'm going to keep working hard and try to figure out why things aren't going my way right now."