No doubt the Vikings played their best first half of the season offensively and defensively against Detroit on Sunday, but after the Vikings led 20-0 at halftime, the Lions outscored them 26-3 and won the game with a field goal in overtime.

If you weren't at the Lions game and didn't watch it on television or listen on the radio and you heard the statistics of the first half, and how largely they favored the Vikings, you wouldn't have questioned that the Vikings won the game.

In the first 30 minutes, the Vikings not only were leading 20-0 but they had 213 total yards to 50 by Detroit and the Lions were outgained 127 yards to minus-7 in the first quarter.

But things started to turn around in the third when the Lions outgained the Vikings 190 yards to 6 and scored 10 unanswered points, then continued to dominate in the fourth quarter.

Defensive lineman Jared Allen was as upset as anybody about the inability of the Vikings to carry their outstanding first-half play into the second half.

"In my opinion, it's not OK to let them score," Allen said later. "It's not OK to let these things snowball again. It's not OK that we've lost three games in the second half. It's not OK that we've given up a 10-point lead, a 17-point lead and now a 20-point lead. That's unacceptable."

If you are a Vikings fan, your head has to be spinning when you realize that in the three losses suffered by the Vikings to the Chargers, the Bucs and the Lions, they have outscored the opposition 54-7 in the first half and then have been outscored 64-6 in the second half. The Vikings still have not scored a second-half touchdown.

Sacked five times Lions quarterback Matthew Stafford, who was sacked five times, completed 10 of 16 passes for 64 yards and no touchdowns in the first half. However, he wound up completing 32 of 46 passes for 378 yards, two touchdowns and a 108.8 quarterback rating.

Calvin Johnson, the great Lions receiver, had one reception for 7 yards in the first half. But he got hot as usual in the second half, turned the game around, and wound up catching seven passes for 108 yards and two touchdowns as the Vikings pass defense, which was so effective in the first half, fell apart in the second half like it had in the two previous games.

Cornerback Cedric Griffin, who was part of the secondary covering Johnson, questioned the fact that many experts consider Johnson the best receiver in the league and almost impossible to cover.

"No he's not, there's no one guy in this league that's the toughest guy," Griffin said. "We just go out there every Sunday and try to give it our best. We believe in our defense and we believe in the guys we have here. We played well, but we let a couple go."

Griffin, like several other Vikings, had no explanation for why they might be the best first-half team in the league and the worst second-half team.

"I have no explanation for that, I really don't," he said. "It's just something that's been happening and maybe this is just something that's testing us right now. So this is our adversity. We're 0-3, but it's definitely something that we can come back from. I have complete faith in my teammates and my coaches and I think we can rebound."

Missed opportunities Despite the poor second-half performance offensively and defensively, the Vikings actually beat themselves with a failure to convert on a fourth-and-1 and two critical penalties in the fourth quarter.

With 11:40 left in the fourth quarter and starting on the Lions 17, the Vikings decided to go for it rather than kick a field goal. They ran a trap play with Toby Gerhart, using Adrian Peterson as a decoy to the outside, and failed to pick up the single yard. The Lions took over and Jason Hanson wound up kicking a field goal to tie the score at 20-20.

Pro Bowl offensive guard Steve Hutchinson could not explain why the Vikings failed to convert on fourth down in a situation that might have won them the game.

"I'm on the ground in the middle of the pile," Hutchinson said. "I'm not the one to ask. We went for it and I guess we didn't get it."

Penalties hurt With 4:13 remaining in the fourth quarter the Vikings drew the first of two big penalties, which really hurt their chances to win. Vikings linebacker Chad Greenway was called for a horse-collar tackle, a 15-yard penalty, at the Vikings 39. That moved the ball to the 24, and eventually the Lions kicked a 40-yard field goal to move into the lead, 23-20.

"I think that was my first [15-yard penalty] ever," said Greenway, who questioned the official about the call.

"Obviously the ref's word is the final word, but I was under the understanding that if I grabbed on the jersey on the front and yanked, it wasn't a penalty," Greenway said. "I thought the horse collar was on the back, on the side, not on the front. I grabbed him right here on the front, it showed on the tape."

About the loss and how the Lions outplayed the Vikings in the second half Greenway said: "We played well, we played well, really, all four quarters, to be honest with you. They got some big plays in the second half, they hit a couple balls, but it wasn't that we weren't defending it well. We played those guys tough. They made some great catches."

And when the clock showed 11 seconds remaining, and the ball was on the Lions 45 with an outside chance for a quick pass completion where the receiver could get out of bounds to set up the winning field goal, Kenny Onatolu was called for a 15-yard roughing penalty, ending the chance of winning the game in regulation.

"You always want to play hard, and that's what I was doing. I thought I was playing to the whistle," Onatolu said. " It's just hard when you feel like you cost your team in a critical situation. That's a tough, hard pill to swallow. I guess they said it was a late hit.

"I saw him standing there and went and hit him. I don't know if it was how hard I hit him; sometimes that draws attention to the play when you have a big hit. They threw the flag."

Sid Hartman can be heard weekdays on WCCO AM-830 at 6:40, 7:40 and 8:40 a.m. and on Sundays at 9:30 a.m. • shartman@startribune.com