Few teams are hotter heading into Week 6 than the San Francisco 49ers.
With a quarter of the regular season already in the books, the Niners find themselves atop the NFC West at 4-1. Their wins thus far have come come in all stripes.
Comeback win? Check. They surprised a reeling Eagles team 24-23 in Week 4.
Ugly win? Check. NFL Films is unlikely ever to take us back to San Francisco's 13-8 squeaker over the Bengals in Week 3.
If they had not caught Tony Romo on one of his heroic days, the 49ers might be sitting at 5-0.
They now face a real undefeated team in Detroit. The Lions are coming off a huge Monday night win over the Bears and are off to their best start since 1956. San Francisco will head into the Lions' den Sunday to spoil the Motown party.
Here's four reasons why they'll hand Detroit its first loss.