The Yankees used Mariano Rivera in the ninth inning on Monday to protect their 10-4 lead. Maybe they were just trying to cheer up the gloomy Twins fans who remained.

Rivera, greeted with enthusiastic cheers when he made a surprise appearance, didn’t get a save for his inning of work. But Twins starter Scott Diamond deserved one: If he was pitching for his job, he probably saved it with his best outing in a month.

But Diamond’s strong 6 ⅔ innings were overshadowed by another poor outing by Jared Burton, the worst night of the season for the Twins bullpen and the prospect of losing cleanup hitter Josh Willingham to a knee injury. Amid all that to worry about, losing yet another game to the Yankees barely seemed newsworthy.

“Tough night,” manager Ron Gardenhire said. “We got to the right guys at the end.”

Usually the Twins bullpen is trustworthy. This time, it surrendered seven runs over the final two innings, removing any chance for the game’s all-time save leader to notch No. 635.

Burton was the biggest culprit, handed a 4-3 lead in the eighth after Chris Parmelee broke a tie score with a home run to the right-field stands. The Twins setup man gave up a leadoff double to Robinson Cano, who already had homered twice — “the one guy we talked about not beating us,” Gardenhire grumbled — and the problems got worse from there. Ichiro Suzuki bunted his way on, as Burton threw the ball past Justin Morneau, and the tying run scored when Burton threw a pickoff attempt into right field. Zoilo Almonte singled Suzuki home moments later, and Burton’s fifth blown save of the year had turned the game around.

Brian Duensing relieved and gave up four runs of his own — seven total runs allowed by the bullpen, a season-high number.

That’s quite a reversal of most of Diamond’s recent starts. Lately, it’s been the starter who surrenders the runs. But Diamond reached the seventh inning for the first time since June 2, and if not for Cano, he would have posted one of his best starts of the year.

Yep, if not for the 435-foot blast to straightaway center in the first inning, or the two-run cannon shot into the left-field seats in the third. When Diamond made a mistake, it was a big one.

“I knew what I needed to do, and that was to work down in the zone. I was just trying to keep it simple,” Diamond said after striking up five and walking only one. “It seems like the past couple of outings, everything has really been speeding up. I’ve been overthinking and questioning. Today, it was just about staying calm and working one pitch at a time.”

Not bad timing, considering Mike Pelfrey was reclaiming his own rotation spot at the same time Monday, pitching six strong innings in a rehab start for Class A Cedar Rapids. The Twins will have a surplus of starters when Pelfrey is reactivated on Saturday, and Diamond might have been at risk.

Now? P.J. Walters, who has had three subpar starts in a row, faces this same lineup on Wednesday, and Gardenhire, pitching coach Rick Anderson and GM Terry Ryan will need to shed a starter by the weekend.

While Diamond was keeping the Yankees, most of them, at bay, Andy Pettitte was reaching a plateau that no Yankees pitcher had reached before. The 41-year-old lefthander struck out Clete Thomas in the second inning, then whiffed Justin Morneau in the fifth, giving him 1,958 strikeouts while playing for New York. That’s one more than Hall of Famer Whitey Ford racked up in his 16-year career.