"It's faster," Castillo said, "when you slide."
The Giants came back from a 4-0 deficit, their biggest comeback of the year. They stayed in the game long enough because of starter Matt Cain, who went eight innings after giving up three runs in the first and earned his fourth win of the season. He struck out eight.
"You can't say enough about how he settled down," San Francisco manager Bruce Bochy said. "He gave us the chance to have a comeback."
Here's a little extra scene-setter on Castillo's dive. Tied at 4 in the sixth, Castillo came up with two outs. He poked a slow grounder to the left side of the infield and sped down the first-base line. His headfirst slide into the bag beat out the throw by a split second.
The hustle sparked the Giants -- and apparently ruffled Royals pitcher Yasuhiko Yabuta.
He walked the next two batters, Omar Vizquel and Fred Lewis, on a combined nine pitches. With the bases loaded, Ray Durham smacked a double to right field off Ramon Ramirez, scoring all three runners.
Durham got his hit on a 2-2 count. He'd already missed on a couple of fastballs, but he hit Ramirez's high, inside heater perfectly.
"Not many people keep that ball fair," Durham said. "I really can't explain it. I'm not going to try to. I'm just really glad I got a hit."
Durham then scored on a Randy Winn double. Not everything was peachy, though. Durham left the game afterward because of a mild right ankle sprain. He hurt it when he planted his foot in the batter's box on his double and said he'd decide Saturday if he'd be ready for the game.
The sixth-inning rally completed what San Francisco started two innings earlier. After struggling against Kansas City starter Luke Hochevar, the Giants got to him for two runs each in the fourth and fifth. They tied the game at 4 in the fifth on Bengie Molina's RBI single.
As for Cain, all he really needed was one inning to warm up. After giving up three runs and three hits in the first, he allowed just two hits, both singles to Joey Gathright, the rest of the way. His only other blemish was an unearned run in the third.
After his tough opening frame, Cain discarded his changeup for the most part and focused on locating his fastball. He sprinkled in a few curveballs and sliders to mix it up.
The performance marked a great change of pace from his previous Interleague starts. Going into Friday, Cain had pitched six times against the American League since beating the Angels in April 2006. He hadn't won once.
That streak is over, and Cain could be ready to start some better ones. After struggling much of the season, he's won two of his past three starts.
"I feel like I've been up and down," Cain said. "I feel a lot more comfortable recently, and I need to keep that mind-set of I'm going to come after guys."
After the game, Cain was in a thankful mood for all of his hitters. Durham, Molina and Castillo each had big hits.
Castillo might not know the scientific answer to the question about the speed of a slide.
But Friday night, it was fast enough. And that's all that mattered.
"I'm happy," Castillo said. "It was a base hit, and we won."