NEW YORK -- Johnny Damon saw it, and thought he had it. Mariano Rivera agreed. But still Damon backpedaled, shifting his gaze up, up, and finally, behind. The ball plunked onto the netting above Monument Park, and Jose Guillen began rounding the bases.

Rivera bent down, picked up the rosin bag and slammed it on the ground. Damon sat on the warning track, staring up at the ball. Manager Joe Girardi sat in disbelief.

"The ball just kept going," Damon said. "I was kind of in shock when it did."

And so Rivera came to lose this game, serving up his second home run in the span of three days. When he allowed the first homer, the Yankees won regardless. This time, they didn't, falling, 3-2, to the Royals on Monday afternoon and settling for a series split.

"I was upset," Rivera said. "In that situation, I have to come and do my job."

It's a job that few have done better in the history of the game -- not to mention this year. Before Saturday, Rivera hadn't given up a home run in nearly 10 months. Then he allowed one Saturday -- "I was shocked," Girardi said at the time -- and the Yankees came back to win.

So on this day, there was nothing but confidence when Girardi handed the ninth-inning keys to Rivera, again asking his closer to preserve a tie game. That plan lasted all of four pitches, just time enough for Guillen to lift an 0-2 offering over the wall in left. Damon, fooled by the ball's flight, staggered a few steps to his left and jumped crookedly toward the ball. Had he chosen a different route, he might have had it. Or perhaps not.

Either way, the Yankees fully expected that they could come back and win -- again. They loaded the bases in the ninth, but Melky Carbrera ended the game with a slow grounder to second.

The loss belonged to Rivera. The bad taste belonged to everyone.

"He's human," Derek Jeter said. "He makes mistakes. But the thing with him is, he forgets about it. The next time he pitches, he won't be thinking about what he did."

The Yankees, however, might. It's difficult to ignore a game in which they had chances -- not too many, but certainly enough -- and couldn't convert. Mike Mussina gave them one of their best pitched games of the year, completing eight innings and allowing two runs. But although Mussina had thrown only 89 pitches heading into the ninth, Girardi wanted this game -- win or lose -- to belong to Rivera. And so it did.

Much of the credit went to Guillen, who produced a .563 average in the series, smacked four home runs and generally kept the Royals afloat.

But the Yankees had hot hitters, too -- nearly all of whom were shut down by Royals starter Luke Hochevar. Bobby Abreu hit a double to lead off the seventh and Alex Rodriguez knocked him in with a homer. That was all the hot hitters could muster.

So they tried instead to go after the Royals' bullpen, and nearly succeeded in the eighth inning. Yet first-base umpire Ed Montague stunted the rally when he called Cabrera out on a sacrifice bunt attempt -- replays showed that Cabrera was safe -- and the Yankees folded again. Cabrera slammed his helmet down and argued, but to no avail.

"There are bang-bang plays," Girardi said. "Some of them are going to go your way, and some of them aren't. That's just baseball. We still had opportunities."

Mussina was just as solid as Hochevar, retiring 11 straight Royals through the middle innings and featuring one of his sharpest curveballs of the year. Both pitchers made one critical mistake -- Hochevar on the Rodriguez homer, and Mussina on Miguel Olivo's two-run shot to open the scoring -- and neither factored into the decision.

But Rivera did, just as he did on Saturday. On that afternoon, he watched as David DeJesus smacked the first pitch he saw over the wall to give the Royals a lead. Then the Yankees rallied and won, and Rivera recorded the win.

An identical scenario unfolded this game. Yet this time, when the Yankees rallied, they didn't win. They lost in spite of it.

So instead of jetting out to Oakland with five wins in their past six games, the Yankees will head west with a series split to the Royals in tow, and a feeling that they might have -- and certainly could have -- performed better. To date, they have won as many games as they've lost, but they insist that they're due for a run.

They did it last year, so they can do it again. It's inevitable -- or at least that's the thought.

"You know, we've been saying that for a month," Mussina said. "'It's inevitable, it's inevitable.' And we're still roughly a .500 team. If it's inevitable, it better start soon. We did something really impressive last year to come back and get to the postseason, being this kind of team at Aug. 1, roughly.

"I don't want to have to try to do that again."