SAN DIEGO – At first, Chase Headley’s power surge seemed like a mirage.

He was going to cool off, right?

As summer dragged on, Headley only got hotter.

The San Diego Padres third baseman has 27 homers and an NL-leading 102 RBI, extending his career bests in both categories and helping to breathe some life into a team that’s out of contention but is playing much better than during its dreadful 19-40 start.

In past seasons, Headley was criticized for not putting up the kind of numbers expected of a third baseman. The 28-year-old came into this year with 36 homers and 204 RBI in parts of five big-league seasons. His previous bests were 12 homers and 64 RBI in 2009, his first full big-league season. Headley played with the Wizards in 2005.

The switch-hitter seems to be making up for lost time with a more aggressive approach and adjustments to his swing that are helping him cope with spacious Petco Park.

“It’s gratifying,” Headley said. “Anytime you face adversity it makes it sweeter when you’re able to overcome that. I don’t run from the type of player I was. It wasn’t for lack of effort, I can tell you that much. I know the guys in this clubhouse at least respected the way I went about it and did everything I could do to help us win.

“Having said that, I knew what I wanted to do and I hadn’t done that. To kind of turn that corner and hopefully be able to sustain that going forward, it means a lot.”

Headley vowed to be a consistent run producer this year, then went on a tear. His 19 homers and 60 RBI since the All-Star break lead the majors. That stretch alone eclipsed the four homers and 44 RBI he had in 2011, when he missed 39 games with a broken finger.

Those around him are impressed.

“When you can sustain this kind of damage for an extended period of time like this, I don’t think you’re running hot anymore. I think you’re just kind of doing what you do,” hitting coach Phil Plantier said.

“He’s always been a good player, but since Aug. 1 he’s been a dominant player,” general manager Josh Byrnes said.

Headley can’t point to any one moment when things started to change.

“I think just once a couple started to happen, it was like then the confidence was there. It’s not like I didn’t believe that it was in there. I hit for some power in the minor leagues. I played in San Antonio and it feels like this place does,” he said, referring to Petco Park. “I knew it was there. But it’s different doing it in the minor leagues and doing it in the big leagues.”

Manager Bud Black said Headley has both a keen eye and a different mindset than in the past.

“I think you’re seeing more aggressive swings early in the count over the last 2 1/2 months,” Black said. “You’re seeing him taking the at-bat to the pitcher. That mindset, being the aggressor, has shifted to the opposition. Where in previous years, as a younger player, they attacked him, now he’s attacking them.”