The rivalry between the Fresno Grizzlies and the Sacramento River Cats will culminate when the teams face off for a five-game series starting Wednesday.

With Fresno leading Sacramento by one game in the PCL South Division standings entering play Monday, the rare five-game series will go a long way in determining the division winner.

Not only are the Grizzlies and the River Cats division rivals, but their Major League affiliates, the San Francisco Giants and the Oakland A's, have also been locked in a rivalry ever since the two teams moved to the Bay Area. Adding extra pressure to the rivalry is an intense Playoff race that will be decided by the showdown at Raley Field.

For many River Cats, this season has been their first experience of the rivalry. But the few Cats lucky enough to have already experienced this clash of franchises are helping clue in the rest of the team.

Relief pitcher Jared Lansford may have the most experience with the Giants vs. A's rivalry. His dad, Carney Lansford, was a member of the 1989 Oakland A's "Battle of the Bay" World Series team that swept the Giants in four games.

"It was cool (growing up with the rivalry)," Lansford said. "Especially being around the clubhouse with all those big name guys, like Mark McGwire, Rickey Henderson, Jose Canseco. I mean I didn't even really have to think about the other team."

The Major League rivalry took hold in Triple-A level when the River Cats came to Sacramento in 2000, setting the scene for the Highway 99 series. River Cats pitcher Brett Tomko, has played with both the Giants and the A's before joining the River Cats this season.

"It's been fun (playing with both teams), I enjoyed both places," he said. "I think anytime you play a rival it adds more to it. It's almost like a playoff game. "It's always fun that they have two big teams in the same market."

Now, at the minor league level, he says the base nature of the rivalry is the same, no matter what level he is at.

"I think a rivalry is a rivalry," the pitcher said, "whether it's big leagues or high school. I think the fact that we are so close in the standings, plus they are the Giants affiliate, all adds to the drama late in the season."

And while both pitchers make it clear that the Major League rivalry has an influence on the Triple-A rivalry, there are distinct differences between the two. While the Giants and the A's are in different leagues, the River Cats and the Grizzlies are not only in the same League, but in the same division. And with the River Cats and the Grizzlies currently battling for a single playoff berth, the rivalry is especially hot this season.

"It definitely adds a little heat to the fire," said second-year River Cat Matt Carson. "I think we're two games back (as of August 16), we have five games coming up when we come back from this next road trip. I don't want to put the whole season on it, but it does basically come down to that (series). We need to be playing our best baseball coming into that."