OAKLAND, CALIF. ? The improbable has become almost inevitable for the Oakland Athletics. Big deficits, bonehead errors and bad pitching all in the same game, no less simply couldn’t derail their amazing 19-game winning streak.

Miguel Tejada had his second straight game-winning hit as the A’s matched the longest winning streak in AL history, beating the Kansas City Royals, 7-6, Monday to extend baseball’s longest run in 55 years.

Oakland players swarm around Miguel Tejada (4) after his game-winning hit in the ninth inning. The A's rallied to defeat Kansas City, 7-6, Monday at Oakland, Calif.

David Justice homered and drove in four runs as Oakland charged back from a 5-0 hole and a terrible start by ace Barry Zito. With Tejada’s bases-loaded single through five drawn-in infielders, Oakland equaled the 19 straight wins recorded by the 1906 White Sox and matched by the 1947 Yankees. The Giants set the major league record with 26 consecutive wins in 1916.

So many things went wrong for the A’s, but nobody in green and gold seemed the least bit surprised to be gathering in the infield for another jubilant, helmet-slapping postgame party.

“I wouldn’t know how to explain it or put it in perspective,” Zito said.

“We’re the Oakland A’s. We’re young. We have fun. Some other teams might be talking about how incredible this is and it is but we do a lot of incredible things.”

With their second straight victory in their final at-bat, the A’s have the fifth-longest streak in major league history and the third longest since 1900.

“I don’t think anybody is going to be satisfied with tying something,” said A’s closer Billy Koch (8-2), who earned his second straight victory while pitching for the fourth straight day. “I think we’d rather break something.”

With the score tied at 6 in the ninth, Tejada rapped a one-out single up the middle. The hit sparked a replay of the raucous Coliseum celebration on Sunday, when Tejada’s dramatic three-run homer beat Minnesota.

For the third straight day, the A’s streak seemed to be in serious jeopardy. In the fifth inning, Oakland trailed 5-0 and hadn’t managed a hit against Kansas City starter Runelvys Hernandez.

But after Hernandez woke up the A’s by zipping a pitch at Jermaine Dye’s head, Oakland rallied with Justice’s two-run homer in the fifth and four more runs in the sixth, capped by Justice’s two-run single that put Oakland up 6-5.

“That’s a great ballclub,” Kansas City manager Tony Pena said. “They believe in themselves and what they can do. We were up 5-0, but they came back and showed what they were after.”

Kansas City tied it in the eighth and loaded the bases in the ninth against Koch, but Tejada artfully turned Neifi Perez’s grounder into an inning-ending double play.

With the pulsating Coliseum sensing another victory, Terrence Long led off the ninth with a triple against Jason Grimsley (3-5) which might have been aided by a fan who threw an orange near left fielder Raul Ibanez.

The Royals intentionally walked Greg Myers and Ray Durham to load the bases. They got Long at home plate on Scott Hatteberg’s grounder but Tejada finished it.

“(Long) hits it off his fist, and some idiot in the stands throws an orange at him, and (Long) ends up at third,” Grimsley said. “There’s nothing we can do but walk the bases loaded with the hottest hitter on the planet up, and nowhere to put him.”

Zito, who complained of dizziness before the game, wasted a chance to become the AL’s first 20-game winner. He yielded 10 hits and five runs in six innings for one of the worst starts of his outstanding career.

Perez had four hits for the Royals, who had 14 hits and plenty of chances to put away the A’s.

The comeback was particularly sweet for Justice and Tejada, who made early fielding blunders that put Oakland in a big hole.

Perez led off the third with a line drive into the left-field corner. Justice sprinted after the ball and leaped at the wall to catch it but the ball hit the bottom of Justice’s glove and ricocheted over the fence, turning a probable double into a homer.

Zito gave up a long homer to A.J. Hinch on his next pitch. Kansas City took a 5-0 lead on three unearned runs in the fourth, thanks to an error by Tejada.

Hernandez retired 12 of Oakland’s first 13 hitters, but he threw at Dye in the fifth. On the next pitch, Dye beat out a grounder for Oakland’s first hit, and Justice followed with his 11th homer of the season.

“When we were down 5-0, the mood in the dugout was real solemn,” Zito said. “When he threw at (Dye), that got us excited. We were up, talking trash. That really woke us up.”

Kansas City tied it in the eighth when Perez scored on Luis Ordaz’s double-play grounder.

Notes: A’s reliever Jim Mecir began serving his three-game suspension for hitting Chicago’s Royce Clayton two weeks ago. … Mike Sweeney, who trails Bernie Williams by one point for the AL batting lead, pinch-hit in the seventh with two runners on and two outs. He flied out to center. … Zito ran head-on into Kansas City’s Aaron Guiel in the fourth when he ran to back up home plate as Guiel was attempting to score on a sacrifice fly. Neither player saw each other coming, but neither was hurt.