After that, Jose Guillen and the Royals took advantage of them.
The Royals hit into double plays in each of the first three innings, but rallied for a 10-5 victory Monday that was aided by four Tigers errors.
"Those double plays were real confidence killers, but we battled through it," said Billy Butler, who drove in a pair of runs. "They helped us out with some errors after that, but 10 runs are still 10 runs. We needed this."
The mistakes meant the end of the Tigers' four-game winning streak.
"We were kind of blah, to be honest with you," Tigers manager Jim Leyland said. "As it turned out, for us it was a very boring game, and for them, it was a very good game. I don't know how many pitches we threw, but it was way, way too many, I can assure you of that."
Detroit's defensive meltdown started in the fourth, just after it had taken advantage of a throwing error by Royals second baseman Chris Getz to score the first two runs of the game.
Butler doubled home a run and Rick Ankiel tied the game with an RBI grounder. Detroit starter Max Scherzer appeared to be out of the inning when Jose Guillen popped a routine foul with two outs, but first baseman Miguel Cabrera dropped the ball.
Guillen followed with his third home run in two games, giving the Royals a 4-2 lead that they never relinquished. The Royals scored seven of their 10 runs with two out.
"We'll take a game like this," Kansas City manager Trey Hillman said. "They made some big defensive plays early, but we kept getting quality at-bats, and they eventually paid off. We haven't had a good two-out approach in the first few games of the season, so I'm happy to see that change today."
Scott Podsednik added four hits, including a two-run single in the sixth that helped the Royals pull away.
"Jose's put together a nice little spurt for us here, and Pod has been great all year," Hillman said. "They both helped a great deal today."
Luke Hochevar (1-0) won despite allowing five runs in five-plus innings.
"I felt strong out there, but I gave up a homer and then I walked a couple guys at the end, which I don't normally do," he said. "They did a nice job of fouling off a lot of my best sinkers, so I adjusted by attacking up in the zone with my fastball, and that worked."
Scherzer (0-1) gave up five runs -- just two earned -- in five innings. He had trouble blaming his defense, however, because one of the unearned runs came after his own error.
After Carlos Guillen hit a solo home run in the Tigers' fourth, Scherzer's throwing error gave the Royals a run in the fifth.
"It doesn't help when I'm out there making errors," he said. "Even at this point of the season, I know we've got a great defense that has made great plays behind me. I know when I go back out there in five days, they will make great plays again. Today, the Royals just took advantage of what we gave them."
Kansas City took control with three runs off Brad Thomas in the sixth. Yuniesky Betancourt and Getz drew two-out walks, David DeJesus hit an RBI single and Podsednik followed with a two-run single for an 8-3 lead.
Brandon Inge pulled the Tigers within 8-5 with a two-run double in the sixth. The Royals scored two more in the eighth, and escaped a bases-loaded jam in the bottom half when Ramon Santiago popped out.
Royals reliever John Parrish worked two perfect innings and has now retired all 10 batters he has faced this season. Hillman said that Parrish would only be available in a very limited capacity for Tuesday afternoon's game against Detroit. ... The game drew 17,058 fans on a chilly afternoon, continuing the opening-homestand trend for Detroit. After drawing 45,010 for Friday's opener against Cleveland, Saturday and Sunday's games drew 35,332 and 26,081, respectively. ... Scherzer, Thomas and Tigers reliever Fu-Te Ni combined for 193 pitches in the game, allowing 20 baserunners.