SAN DIEGO -- Well, there goes the Dodgers' undefeated season.

The reigning National League West champions and kings of Australia's Opening Series were six outs away from another happy ending on Sunday night when Seth Smith announced his presence to his new fan base.

Making his Padres debut leading off the eighth inning against Brian Wilson, Smith lifted a 2-0 cut fastball into the right-field seats at Petco Park for a game-tying home run. A walk, two errors and Chris Denorfia's two-run single finished Wilson, had Hyun-Jin Ryu wondering what happened to his second victory and left San Diego fans in a record crowd chanting "Beat L.A."

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The Padres did just that, taking out the Dodgers, 3-1. The Major Leagues' opener on North American soil gave the 2014 season a resounding liftoff.

"They're always tough -- great hitters, great pitchers," Padres ace Andrew Cashner said, having gone six innings in a spirited duel with Ryu. "You have to play perfectly to beat those guys."

Ryu, who beat the D-backs in the second game in Sydney, has yielded five hits and no runs in 12 innings. After a rough start, he retired 15 Padres in succession and had disposed of 17 of 18 when he was replaced after 88 pitches and seven innings by manager Don Mattingly.

History suggested that Wilson vs. Smith was a good idea. Acquired from the A's in exchange for valued reliever Luke Gregerson, Smith was 0-for-5 in his career against the former Giants closer, with three strikeouts. But that was when they wore different uniforms.

The dynamic clearly changed as Wilson unleashed to back-door a cutter that came in the front door. Smith unloaded.

From there, it completely unraveled for Wilson, who couldn't field Everth Cabrera's bunt for an error after walking Yasmani Grandal on a full count, a 2-2 pitch at the knees having gone the hitter's way.

"Two-oh, you're looking to get something over the plate," Smith said. "Anything over the plate, you're going to swing at."

This was what San Diego manager Bud Black had in mind when the club acquired Smith, the Majors' leading active pinch-hitter with a .315 batting average and six homers in 168 at-bats.

"His role is a left-handed bat off the bench for situations like tonight," Black said. "That's how we envisioned it. He got ahead in the count, Wilson had to come in, and Smitty put a good swing on it."

The Padres partisans in the throng of 45,457 were still roaring when Denorfia came up with runners on second and third after a Grandal steal and Cabrera's advance on defensive indifference. Denorfia had faced Wilson four times previously without making an out: three singles and a walk.

Working the count full, the hard-working right fielder slammed a base hit through the middle. Wilson, close to perfect for the Dodgers late last season and in the postseason, was brought back for $10 million to set up for closer Kenley Jansen and handle moments such as this.

Wilson endured a nightmare that makes short memories a must for short relievers, and the Padres, not the Dodgers, were leading the NL West.

Black, San Diego's upbeat leader, promotes a freewheeling approach, no fear of failure clouding his athletes' minds. Flying beneath the national-media radar is irrelevant to Black.

"I think players like expectations," he said. "I think most players like pressure. We talk about that. I want our guys to play loose and fearless -- regardless of the type of market we're in."

The Padres pressured Ryu out of the chute. Cabrera walked leading off and raced first to third on Denorfia's bullet gloved by Yasiel Puig in right field. As Puig's laser throw was cut off by shortstop Hanley Ramirez, Denorfia darted into second.

Ryu escaped, getting Yonder Alonso to bounce into a 1-2-3 double-play, but a tone was set.

"Our style of play over the years is we have to push it a bit to score runs," Black said. "We have to be aggressive on the basepaths. At times we might give up an out, but being aggressive outweighs the negatives. Our guys like to play that way."

Grandal's steal of third, the first theft of his career, was "huge," Black said. "He's an instinctual player. He saw [third baseman Juan] Uribe in for the bunt. We talk a lot about game awareness."

It paid off again when Cabrera took second without a throw, giving his team a big insurance run as Denorfia delivered.

The Padres finished strong last year, tying the Giants for third in the division. They feel they have something going on here that a come-from-behind win against the Dodgers can only enhance.

"It's just nationally, we're under the radar," said Cashner, the young Texan who wears No. 34 for his boyhood idol, Nolan Ryan. "We have a lot of good players in here, guys to count on. Knowing your role is huge."

Cashner's role in the fifth inning, with the Dodgers threatening to break it open after Carl Crawford's RBI single, became crystal clear. If he couldn't retire Ramirez with the bases loaded, the game could get out of hand.

"It's a long inning," said Cashner, who'd faced six hitters before confronting Ramirez, "and you can't allow them to do any more damage.

"I didn't execute against Crawford, and I have to bear down and think about making a good pitch to Ramirez. No more mistakes. I got a sinker in a good spot and got out of it. That was big."

Ramirez's grounder to Cabrera at short ended the threat. The bullpen took care of the final three innings, and Smith and Denorfia -- showing no fear of the beard -- came through.