David Ortiz is saluted by teammate Kevin Youkilis after rounding the bases for the 300th time as a Red Sox. (AP)

For nine extraordinary years, David Ortiz has been circling the bases for the Red Sox. In the process, he has cemented his place in franchise history in innumerable ways.

On Saturday night, he added to his long resume as one of the franchise greats. In the bottom of the fourth inning, with a 2-2 count and a runner on first, Ortiz stayed back on a 93 mph fastball that was elevated on the outer half of the plate. With a swing that would make teammate Adrian Gonzalez proud, he launched the ball just over the Green Monster for his ninth homer of the year, and his 300th as a member of the Red Sox.

Ortiz became the fifth player to accomplish that feat with the Sox, joining Ted Williams (521), Carl Yastrzemski (452), Jim Rice (382) and Dwight Evans (379).

“I heard people talking about it yesterday for the first time,” said Ortiz. “It’s an honor for me to be mentioned in that category with those guys that played here for a long time. Through the years, they were putting up great numbers.”

Ortiz, of course, has been doing the same thing. That is true not just of his career in Boston, but also of a 2011 season that has seen him get off to his best start since 2007.

The Sox DH now has five homers in his last 10 games, giving him nine on the year — tied with Adrian Gonzalez for the most by a member of the Sox. He is hitting .294 with a .370 OBP, .525 slugging mark and .894 OPS, ranking in the top 10 in the AL in slugging, OPS and homers.

Of particular note, however, has been the fact that Ortiz has been crushing the ball to left and left-center, and that he has cut down his strikeouts considerably. In fact, Ortiz has walked as many times (20) as he’s struck out. In fact, his strikeout rate (once every eight plate appearances) is at its lowest since he came to the Sox in 2003, something that Ortiz believes is at the heart of his early-season success.

“Just trying to stay in the strike zone, try to not get out of it,” said Ortiz. “When I get out of it, I get in trouble.”

That hasn’t happened often in his Red Sox career, and it hasn’t happened often in 2011. As a result, while Ortiz passed one milestone, it didn’t seem like a gold-watch accomplishment that he might ride off into the sunset. Instead, the DH is on pace once again to clear 30 homers, meaning that he reached his milestone on Saturday night in a fashion that does justice to the way that he reached it.

“Pretty amazing, isn’t it?” marveled teammate Jason Varitek. “He’s done a lot and he’s continuing to do what he does and swinging the bat real well.”