MLB

A-ROD SEVENTH FUELS GREAT 8

The MRI exam on Alex Rodriguez yesterday showed no serious damage to his right ankle, just a plate embedded in his midsection. It’s a rare condition known as “guts of steel.”

First, Rodriguez talked his way into the starting lineup last night. Then he slammed two home runs in one inning, leading the Yankees to their most important series victory to date.

In all, the MVP with the MRI delivered three RBIs in the Yankees’ 10-2 demolition of the Mariners at the Stadium. The Yanks now lead Seattle by three games and Detroit by 3½ in the AL wild-card race.

Rodriguez belted homers No. 47 and 48, tying the single-season franchise record he established in 2005 for a right-handed hitter. That was the highlight of an eight-run seventh inning for the Yanks that all but ensured Joba Chamberlain (1-0) of his first major league victory.

“There’s not much time left,” Rodriguez said. “I guarantee you if it were April or May I would have taken a day [off], there is no question about it.”

Earlier in the day Rodriguez underwent an MRI exam that revealed a sprained and bruised right ankle, the result of an entanglement with Adrian Beltre while sliding into third base a night earlier.

Joe Torre wanted to rest Rodriguez last night, but that plan was scrapped after A-Rod returned from Columbia Presbyterian Medical Center around 6 p.m., ran in the outfield and declared he had to speak with the manager. Rodriguez was inserted as the DH, bumping Jorge Posada from the starting lineup.

Rodriguez’s homer leading off the seventh against Jarrod Washburn made it 2-2 before the Yankees erupted. A-Rod delivered the knockout punch in his second at-bat of the inning with a two-run homer against Brandon Morrow. Melky Cabrera had a key RBI single and Derek Jeter smashed a two-run double in an inning that saw Seattle use six pitchers.

All the while, the Yankees got everything they could have wanted from Phil Hughes and Chamberlain before Edwar Ramirez and Mariano Rivera mopped up.

“We needed that one,” GM Brian Cashman said as he waited for an elevator after the game. “Phil Hughes was awesome.”

The right-hander, in his sharpest performance since defeating Cleveland on Aug. 10, allowed two earned runs on five hits with six strikeouts and two walks. The only thing missing was a victory next to his name.

“Especially coming off three not very good starts, this is one I can definitely work off of,” Hughes said.

Raul Ibanez’s two-run homer in the third gave the Mariners a 2-0 lead after the Yankees had received a gift call moments earlier. Ichiro Suzuki was called out attempting a steal of second, though replays revealed a phantom tag by Jeter. Suzuki stood up mid-slide and Jeter made a swipe, close enough as far as umpire Gerry Davis was concerned.

Jose Guillen singled to begin the two-out rally before Ibanez homered into the right-field seats. It was the fifth home run surrendered by Hughes in his last three starts.

The Yankees got a run back in the bottom of the inning on Jose Molina’s leadoff homer. It was Molina’s first homer of the season, ending a drought of 182 at-bats, dating to Sept. 16 of last season. It stayed at 2-1 until Rodriguez’s bomb leading off the seventh.

Now the Yankees get a nine-game road trip through Kansas City, Toronto and Boston, a stretch in which they’ll try to make the race a runaway.

“Even though it doesn’t seem like it, we were 6-3 on this homestand,” Torre said. “That’s not too bad.”

mpuma@nypost.com

Yankees 10 Mariners 2