OAKLAND -- Jim Johnson is perplexed by his struggles when he believes he is throwing good pitches.
Yes, the 2013 AL saves leader hears the boos in his home ballpark -- and there were more during the A's 5-4 loss to the Detroit Tigers on Thursday.
"What am I supposed to do?" Johnson said of the crowd treatment. "I don't know what to tell you. Balls are finding holes. I'm throwing pretty good pitches, I just feel like I'm in a little bit of bad luck. I don't think it's as bad as it really seems. I think everybody else thinks that way."
Two of the American League's top teams have struggling closers who are accustomed to being among the best in baseball.
Joe Nathan held on through another rocky ninth inning for his 13th save a day after blowing one in a May matchup of division leaders.
"If Joe's on you're going to have quick outs. He's been one of the best closers, he had an unbelievable year last year," Tigers manager Brad Ausmus said. "If he's on, he'll get quick outs. It just wasn't today."
Miguel Cabrera hit a go-ahead sacrifice fly in the fifth to back Rick Porcello's eighth victory.
Porcello (8-2) overcame a career-high six walks, three shy of his season total coming into Thursday's start. Nathan allowed Josh Donaldson's leadoff double, an RBI infield single by Yoenis Cespedes and Josh Reddick's run-scoring double before pinch-hitter Jed Lowrie grounded out to end the game.
It was Nathan's first outing since he surrendered Donaldson's game-ending three-run homer in Wednesday's 3-1 loss for his fourth blown save opportunity.
"You guys can get the guys that did their part. You can write whatever you want," Nathan said.
Victor Martinez doubled home two runs in the seventh and Cabrera also had an RBI groundout for the Tigers, who head to Seattle for the weekend before returning home.
Nick Punto hit a two-run homer in the fourth for Oakland, which wasted chances all game to lose for only the seventh time in 20 games.
"We had plenty of opportunities," manager Bob Melvin said. "We had some situational at-bats where we didn't come through."
Porcello moved into second place in the AL for wins behind Toronto's Mark Buehrle.
He did just enough this time, coming off just his second loss of the year Saturday against Texas in which he was tagged for eight runs and 12 hits in 5 1-3 innings.
"It's no secret I was all over the place," Porcello said. "I was fortunate to get out of some of the innings."
Porcello improved to 5-1 on the road. He allowed five hits and two runs with four strikeouts in 5 2-3 innings.
Oakland starter Jesse Chavez (4-3) lost consecutive starts for the first time this season following a two-game winning streak.
His pitch count went up in a hurry. The right-hander walked two of his first three batters but escaped a rough first inning unscathed.
After Ian Kinsler lined out to start the game, Chavez walked the next two and received a mound visit from pitching coach Curt Young after going to 2-0 on cleanup hitter Victor Martinez. Martinez then singled and J.D. Martinez grounded into an inning-ending double play.
The A's left the bases loaded in the second and sixth innings, and also squandered scoring chances in the first, fifth and seventh. They had the tying run on second and go-ahead run on first to end the game, leaving 14 on base in all.
"That's the game of baseball, that's going to happen," Chavez said. "Unfortunately today we didn't get that big hit."
AL Central-leading Detroit, which eliminated the two-time defending AL West champion A's in a five-game division series each of the past two Octobers, won for just the third time in 11 games following a six-game winning streak.
NOTES: Tigers OF Rajai Davis, formerly with Oakland, was held out of the lineup with lingering soreness in his left shoulder that he hurt while diving for a fly ball during the second inning Wednesday night. ... Ausmus decided to give 38-year-old Torii Hunter an unscheduled day off. "We've got to give him a day off because he's an old man," Ausmus joked. "We need him for the long haul." ... A's setup man Ryan Cook, on the DL since May 9 with a forearm strain, threw a bullpen session and could begin a rehab assignment within the next week. ... Oakland's Drew Pomeranz (4-2), who pitches the series opener against the Angels on Friday, has won three of his four starts since being moved into the rotation.