On a rare visit to Petco Park, the Royals started the hardest thrower in baseball. Yordano Ventura, a 22-year-old fast establishing Rookie of the Year candidacy, fired aspirin tablets toward the plate.

By comparison, Eric Stults proved a most comfortable at-bat. Monday, the free-swinging Royals amassed 10 singles and a double against Stults, a 34-year-old left-hander dependent on guile and location. Coming off 2 ⅔ innings in San Francisco - that tying the shortest start of his well-traveled career - Stults did not surpass that mark by much, somehow limiting the damage to three runs.

That was before the cavalry arrived. Not once, but three times.

In a 6-5, 12-inning, walk-off triumph, the Padres achieved what they have so often failed to do. Down multiple runs, they tied the game, on Yasmani Grandal’s sixth-inning, three-run homer. Down again, they pulled even once more when Jedd Gyorko crushed a solo shot in the ninth, with just two outs to spare. Down yet again, they took the game nearly to the four-hour mark.

In that final inning, with the Royals ahead 5-4, Chris Denorfia singled. A sacrifice bunt by Alexi Amarista, who had saved a run with a throw home in the 11th, moved Denorfia to second. Yonder Alonso lifted a pitch to shallow left, the ball landing just in front of a diving Alex Gordon for a bloop double. Then, Will Venable hammered a two-run single to right, and the Padres streamed out of the dugout to celebrate what may well have been their most satisfying victory of the year.

“Every win is satisfying, but yeah, tonight was a fun one,” said Alonso, who came off the bench for a second consecutive walk-off win.

“We’ve seen a lot of things in this game. This game will do a lot of crazy things to you. … You’ve just got to stay positive. You just have to continue to work.”

Following a couple of dismal losses to Arizona, the Padres offense, mired in a five-week, season-opening slump, has stirred over the last two contests. Sunday’s 4-3 win, delivered on Alonso’s soft groundout RBI, preceded San Diego’s second two-homer game of the year, this one coming at the most opportune of junctures.

“We’re seeing some subtle signs of some harder contact, some better swings,” Padres manager Bud Black said. “These are the types of games that can lift certain guys based on the game that they had.”