MINNEAPOLIS — MINNEAPOLIS It was a tight pitcher’s duel. And then it wasn’t. Then the Royals had a comfortable lead with their most reliable starter on the mound. And then they didn’t. And what started Friday as a promising weekend ended Sunday in disaster.

The Minnesota Twins erased a four-run deficit in the sixth inning when Bruce Chen, who had been cruising along, served up booming homers to Josh Willingham and Trevor Plouffe in what turned into a 10-8 loss at Target Field.

“I feel bad,” Chen said. “We had a good lead, and I feel like I let the game get away from me. I have to make much better pitches and, at least, preserve the lead.”

The Royals had just scored four runs in the top of the inning but, after Minnesota answered with a five-spot, never fully recovered.

Drew Butera supplied the knockout punch with a three-run homer in the eighth against reliever Aaron Crow. It was Butera’s first homer of the season, but the Twins’ fourth of the day.

“It got away in a hurry,” manager Ned Yost said. “The homers buried us.”

Butera’s homer also allowed the Twins to survive the Royals’ three-run ninth against Glen Perkins. The Royals got four straight two-outs hits but fell short. It was that sort of weekend.

It all sent them limping toward Toronto with a three-game losing streak after opening the series Friday by holding on for a 4-3 victory. They appeared lifeless Saturday in losing a double-header but seemed poised Sunday to gain a split.

Until they didn’t.

“We came in here looking to get some wins against a Central (Division) team,” left fielder Alex Gordon said. “It started great, but the double-header didn’t go very well, and it went downhill from there.”

It was two different games, really. Chen, 7-7, and Twins starter Francisco Liriano were dominant for five innings. Chen permitted just one hit, albeit a homer by Plouffe; Liriano yielded one run on four singles.

Then everything changed.

The Royals knocked out Liriano by striking for four runs in the sixth after Yuniesky Betancourt’s one-out single through the left side. Betancourt went to second when Liriano skimmed Eric Hosmer with a pitch.

Brayan Peña’s high chop to the mound caromed off Liriano’s glove and away from everyone for a single that loaded the bases.

The big break, or so it seemed, came next when Jason Bourgeois’ grounder bounced through first baseman Justin Morneau for one error and through right fielder Darin Mastroianni for another error.

Two runs scored, and the Royals wound up with runners on second and third. The official ruling was a fielder’s-choice prior to Morneau’s error, which meant Bourgeois got credit for one RBI.

That was it for Liriano, but not the Royals. Irving Falu lashed a 2-0 fastball from reliever Jeff Gray into the right-field corner for a two-run double and a 5-1 lead.

“When we scored the four runs,” Yost said, “I’m thinking, `OK, we’re in great shape. Bruce is rolling, and we’ve got a pretty stocked pen.’ But it didn’t turn out that way.”

The Twins quickly got it all back and more.

Brian Dozier opened the Minnesota sixth with a triple over Bourgeois’ head in center. Denard Span’s sacrifice bunt made it 5-2. A walk to Jamey Carroll and a single by Joe Mauer put runners on first and second with one out.

Willingham tied the game with a moon shot into the bullpen to the left of dead-center field. Chen struck out Morneau, but Plouffe followed with his second homer of the game.

It, too, was a no-doubter, and the Twins led 6-5 – and Chen exited.

“I definitely can’t walk Carroll in that situation,” he said. “I really felt like I had all of my pitches going, and I shouldn’t have given up six runs – especially since we were ahead 5-1.”

Minnesota added an insurance run in the seventh against Kelvin Herrera and José Mijares before Butera’s three-run shot in the eighth against Crow made the hole too deep. Gray, 4-0, got the victory.

The three straight losses dropped the Royals to 35-42, which means only a 7-0 run through Toronto and Detroit can enable them to achieve their goal of climbing back to .500 by the All-Star break.

“It was a crummy weekend,” right fielder Jeff Francoeur said, “and we’ve got to find a way to go to Toronto and put this behind us. They’re really hitting the ball right now, but we owe them a little payback after what they did to us early in the season.”

The Blue Jays swept a four-game series in April at Kauffman Stadium. Those were losses eight through 11 in a 12-game skid that continues to haunt the Royals.