Jason Giambi was the American League Player of the Month when he batted .355 with 24 RBI in July. In August, he found himself locked in slumps of 0-for-21 and 4-for-38.

Same guy, same swing, different results.

The good Giambi made an appear ance yesterday with two home runs and a single, driving in seven runs in the Yankees’ 10-3 victory over Kansas City. The spurt pushed Giambi past two personal milestones – 1,500 hits and 1,000 RBI.

That was news to him, delivered by manager Joe Torre.

“I really didn’t know [about the milestones],” Giambi said. “Actually, Joe’s the one who congratulated me. I said ‘For what? I know I haven’t had a hit for a while.’ “

When Giambi hit the first homer, Torre wasn’t surprised to see the second.

“Normally, power hitters hit them in bunches,” the manager said. “His swing is compact at this point in time. I look forward to tomorrow to see where he hits it.”

Giambi said his left elbow, diagnosed with tendinitis, felt better.

“I feel like I’ve got my bat speed back,” he said.

Giambi’s first homer in the third inning was a three-run shot. He followed that with a two-run homer in the fifth and a two-run single in the sixth. Bernie Williams drove in the other three Yankee runs with a pair of singles.

Both of Giambi’s homers came against Zack Greinke (3-16), who lost for the fifth straight time. His 16 losses are the most for any pitcher in the majors.

“Sometimes, I think I do decent, but it will just find a way to happen,” Greinke said. “Even if I pitch about as I good as I have pitched, they’ll find a way, some way, to score runs and win the game when I’m pitching. Today I didn’t really give us a chance. They’ve got some great hitters and early on they were hitting my pitches pretty much, but later in the game, I was messing up.”

Manager Buddy Bell said it was not one of Greinke’s better starts.

“His location really wasn’t very good and it’s a tough lineup,” Bell said. “Especially when they’re swinging the bats like they are, it’s tough to deal with, and when you don’t have your best stuff, you’re going to struggle a little bit.”

Giambi’s two homers gave him 23 for the season.

It was his sixth multihomer game of the season and the 29th of his career.

Al Leiter (4-3) earned his third straight win, limiting the Royals to two hits in six innings. He struck out six, walked three, and threw 112 pitches after reaching 75 after three innings.

“I look at this as a second life,” Leiter said. “Every game feels like an event. Every pitch matters. I need that. It elevates your aggressiveness.”

The Yankees jumped in front in the first inning when they loaded the bases on walks to Hideki Matsui and Giambi sandwiched around a single by Gary Sheffield. Williams then bounced a two-out, two-strike single into right field, scoring Matsui and Sheffield.

The Royals picked up a run in the third but could have had more after Denny Hocking opened with a walk and Joe McEwing doubled. After David DeJesus’s run-scoring groundout, Leiter walked Chip Ambres and Mike Sweeney to load the bases.

Leiter recovered to get Emil Brown and Terrence Long, ending the inning. He then retired nine of the next 10 batters. Sweeney hit his 19th homer, a two-run shot in the eighth.