CINCINNATI -- It wasn't a hunch, though it certainly would have been a better story had San Diego manager Bud Black just come out and said the changes he made to his original lineup on Friday were nothing more than intuition, a gut feeling, even.

The truth is, when the Padres were informed late-afternoon that the pitcher scheduled for Saturday, Bronson Arroyo, would be pitching on Friday, Black inserted into the lineup two left-handed hitters he would have used on Saturday anyway.

Those two hitters, Matt Stairs and Tony Gwynn, keyed a four-run second inning with big hits that propelled the Padres to their seventh consecutive victory, this a 10-4 victory over the Reds before a crowd of 15,183 at Great American Ball Park.

"Today we made him look good," Gwynn joked of Black's maneuvering of the lineup.

Stairs, in his first start of the season, had a two-run double in the second inning, and two batters later, Gwynn hit a two-run home run as the Padres (10-6) started a six-game road trip to Cincinnati and Florida with a resounding pop.

Runs, something that were hard to come by in 2009, are proving to be plentiful for these Padres, who have already scored 10 or more runs in a game this season. Last season, the Padres didn't hit double-digits in runs for a second time until their 104th game (July 31).

"I just think we have a lot of guys who put [together] quality at-bats," said Padres' first baseman Adrian Gonzalez, who slugged his second career grand slam during a six-run, fourth inning as the Padres opened a 10-0 lead over the Reds (7-10).

"Arroyo made some quality pitches just off of the plate and we didn't go after them."

The grand slam moved Gonzalez into fifth place on the Padres' all-time list with 134 home runs.

In all fairness, the Padres didn't look at too many pitches on Friday. They finished with 15 hits in the game, as every starter, with the exception of pitcher Kevin Correia (3-1) had at least one hit.

Chase Headley opened the second inning with a single and raced to third base when Will Venable doubled. That brought up Stairs, who until Friday had but eight at-bats to show for the first 15 games of the season.

Stairs, who made his Major League debut in old Riverfront Stadium in 1992, watched a strike go by on a curveball and then hammered the next pitch, also a curveball, into the corner in right field for two runs.

Two batters later, hammered a curveball as well, sending it into the Padres' bullpen past the right-field fence for a 4-0 lead and his third career home run. Gwynn felt that scoring runs early in the game was critical, especially with so many runners on base.

"It's important against every Major League pitcher to get on them early," Gwynn said. "Bronson is tough because he throws the kitchen sink at you."

Correia didn't have to work as hard. He cruised through the first five innings, walking two and striking out five while allowing no hits. His flirtation with a no-hitter, which would have been the first in club history, ended when Ryan Hanigan doubled to deep center field to start the sixth.

Correia, who allowed two runs in the sixth inning and left after 5 2/3 innings, wasn't at all disappointed with the offensive backing he received. In four starts, the Padres have scored 29 runs for him, including 17 in the home-opener on April 12.

"I'm never going to complain. I'd go five innings every time if we're going to win and score like that," Correia said.

As for the change in lineup, Black said it was a combination of getting his bench players -- like Stairs, in this case -- a start and keeping him fresh and his preference of getting as many left-handers in the lineup against Arroyo (0-2) as possible.

So, maybe it was a little bit of a hunch after all?

"We felt left-handed hitters against Arroyo was the way to go," Black said. "We have the flexibility to do that with certain pitchers."