The righty was staked to an early 3-0 lead in the first inning, but the Yankees chipped away until the fifth, when they jumped on Santana for four runs to take a 7-4 advantage. Still, Santana survived the frame and had a chance to extend his streak of six-plus-inning starts, but he promptly surrendered back-to-back singles to start the sixth before manager Ned Yost turned to the bullpen.
"If you've watched Ervin all year long, he's been a guy that goes deep into games -- six and seven innings," Yost said. "He usually finds ways to make a big pitch when he needs to. … He got through [the fifth], and I wanted him to regroup and get us through the sixth, but once those two guys got on, I had to make the move. I know he's capable of doing it."
Santana admitted that he had trouble with his command for much of the day, especially when the wheels came off in the fifth inning. Following a one-out walk to Ichiro Suzuki, Santana forced Jeter to ground out for the second out of the inning, but the righty had trouble finishing the frame.
Yost elected to have Santana intentionally walk Yankees All-Star Robinson Cano, but Santana followed that with another walk to Vernon Wells, loading the bases with two outs for Lyle Overbay.
Overbay, who put the exclamation point on Wednesday's rout with his fourth career grand slam, came through once again with the bases loaded on Thursday. With the Royals clinging to a 4-3 lead at the time, Santana conceded a two-out, two-run single to Overbay, putting the Yankees ahead for good. New York followed with back-to-back RBI singles from Zoilo Almonte and Eduardo Nunez, the second of which ended with Almonte being thrown out at third base to end the frame.
"After I got the first out, I don't know what happened," Santana said. "Ball one, ball two, ball three, ball four. I was trying to take a deep breath and go back and I couldn't find it."
Santana allowed each of the final seven batters he faced to reach base, finishing the day by allowing eight earned runs on 10 hits, both season highs. With the loss, Santana fell to 0-6 with a 7.30 ERA in nine starts against the Yankees since the start of the 2009 season, including 0-3 with a 9.72 ERA in three starts at the new Yankee Stadium.
"I don't think that way," Santana responded when asked about his struggles in the Bronx. "It doesn't matter where I'm pitching, I just go out there and do my best every time."
The rocky outing came just one day after fellow starter Wade Davis was also tagged for eight earned runs in a lopsided 8-1 loss on Wednesday night. Santana and Davis became the first Royals starters to allow eight or more earned runs in consecutive games since Aug. 13-14, 2006 (Luke Hudson and Mark Redman) and the first Royals duo to do so while each pitching five or more innings.
Making matters even worse for Santana was the fact that his offense had provided him with an early three-run cushion.
Kansas City made its best attempt to dampen Jeter's return early, storming out of the gates to a three-run lead in the top of the first inning. After sitting out Wednesday's contest to rest his sore right calf, All-Star catcher Salvador Perez delivered a bases-loaded, two-run double to start the scoring. Lorenzo Cain followed with a sacrifice fly to extend the lead to three.
The Yankees quickly rallied in the bottom half of the inning, starting with an infield single by Jeter in his first at-bat of the season. The Yankees' captain moved to third on a Cano base hit and came in to score on Wells' sacrifice fly, putting the Yankees on the board.
Though the Royals got the run right back in the top of the second courtesy of an Alcides Escobar RBI single, the Yankees answered again against Santana with two runs of their own in the bottom half to cut the lead to 4-3. It would stay that way until the Yankees' fifth-inning eruption.
"It's kind of frustrating, because any time you get four runs, it's my job to just keep the lead," Santana said. "So it's my fault today."
Once the lead slipped away, the Royals were unable to get it back with their bats falling silent after racking up four runs in the first two innings against Yankees veteran Andy Pettitte. In all, Pettitte went on to pitch 5 2/3 innings without allowing another run before turning it over to the bullpen for the final 3 1/3 frames.
"Against a guy like that, you try to work the count as much as you can, and I thought we did a good job of that early," said Royals right fielder David Lough, who went 3-for-4 with a run. "Then he started settling in a little bit, and he just pitched a good game from there on out."
Thursday's series finale was, in a way, reminiscent of the series as a whole, with the Royals ultimately letting the Yankees come back and salvage a split after Kansas City won the first two games of the four-game set.
"I feel that we definitely had a chance to win this game, especially with the early lead," Yost said. "But it just didn't happen today."