DENVER -- There was Ryan Klesko's grand slam, a two-run inning in which the ball never left the infield, and a botched run-down that most Little Leaguers could execute.
"When I wake up in the morning, I don't want to remember this happening," Rockies starting pitcher Jamey Wright said.
Klesko's ninth career grand slam was the highlight for the Padres, who extended their lead in the division to 5½ games over Arizona and are guaranteed of heading into the All-Star break with a winning record for just the ninth time in franchise history.
He took an 0-1 pitch off Byung-Hyun Kim to right-center field to cap San Diego's six-run sixth inning and put the Padres ahead 10-2. It was Klesko's first homer since June 22 and a nice start to the series after he went 1-for-14 against the Astros in Houston.
"That's baseball," Klesko said. "I'm not going to spend a lot of time trying to figure that out. I've really been smoking the ball the last couple of weeks, and I've got nothing to show for it."
Klesko's slam, his first since August 27, 2002, secured the second consecutive victory for Tim Stauffer (3-4), who pitched seven innings, allowing five hits and two runs and striking out five.
Wright (5-9) gave up six runs in 5 1/3 innings for the Rockies, who matched their most lopsided loss of the season and started bumbling well before Klesko's homer turned the game into a laugher.
The Rockies were ahead 2-0 in the third inning when Brian Giles doubled to score Dave Roberts. Todd Helton cut off the throw home and trapped Giles between second and third, but third baseman Garrett Atkins threw the ball into center field as Giles scored and tie the game at 2-2.
The next batter, former Rockies pinch-hitter Mark Sweeney, homered off Wright to make it 3-2 and San Diego piled it on from there.
Sweeney was Colorado's top pinch hitter in 2003 and 2004 but left Denver after last season -- one of several veterans the Rockies parted ways with to cut costs and begin a bona fide youth movement.
The youngsters took a step backward on this night, just one game after Helton hit two homers, and became the franchise's all-time home run leader, in a come-from-behind 8-5 win over the Dodgers.
In that game, Coors Field was abuzz. A day later, the excitement was replaced by booing.
"Nobody likes to go out and get embarrassed," Colorado manager Clint Hurdle said. "We didn't play well. We had a rough night at the ballpark."
The Rockies committed two errors and failed to make a number of plays in the infield. One of the many low points came in the eighth, when reliever Dan Miceli allowed two runs on three infield hits, a walk and a hit batter to make the score 12-2.
Meanwhile, Colorado's only offensive highlight came from a player who probably won't be around much longer. Preston Wilson, the subject of trade talks with the Washington Nationals among other teams, hit a two-run homer in the first.
Klesko had two hits. His homer was his team-leading 14th of the season and gave him 40 RBI. He also made a diving catch in left field to steal a hit from Cory Sullivan to end the second inning.
Khalil Greene had two hits and two RBI for the Padres, who finished with 14 hits.
"It's been a while since we won one like that," Padres manager Bruce Bochy said.
Kim replaced Bobby Seay, who left with inflammation of the thumb on his throwing (left) hand. He'll have an MRI on Saturday. ... Giles has now reached base safely in 21 of the last 23 games. ... The Rockies hit two batters to bring their NL-leading total to 59. ... Desi Relaford went 0-for-4 and is now hitless in his last 26 plate appearances. ... The Padres have won their last five against the Rockies.