Eugene — On Oct. 19, the 6-0, sixth-ranked Oregon football team cruised to a 21-0, second-quarter lead against Arizona State at Autzen Stadium.

A month later, the Ducks are 7-4 and unranked heading into their regular season-concluding Civil War clash at Oregon State on Saturday at 12:30 p.m.

The shocking, four-losses-in-five-games collapse begs the question: What happened?

While it’s obvious Oregon wasn’t a true national-title contender this fall, it’s also evident confidence — or the lack thereof — can do wonders on a college football field.

When Arizona State rallied for a 45-42 win on the strength of scores on eight straight possessions and quarterback Andrew Walter’s 536-yard passing spree a month ago, the Ducks’ demise — both in record and self-belief — began.

A week later, Southern California turned a 19-14 halftime deficit into a 44-33 victory behind 30 unanswered points at Autzen.

Oregon did post a 41-14 home victory over Stanford on Nov. 2, but that only postponed the slide.

It was Washington State’s turn in Pullman, Wash., Nov. 9, a 32-21 win for the Cougars.

And even a mediocre Washington team got into the act last week at Autzen, crushing the Ducks, 42-14, in what had to be Oregon’s worst performance in years.

"Guys are very frustrated," senior wide receiver Jason Willis said following the latest loss. "It’s the low point (of my career)."

In retrospect, it seems that the Sun Devils’ comeback to hand the Ducks their first loss of the fall not only exposed Oregon’s deficiencies — i.e. its secondary — to others, but it also injected doubt into the Ducks themselves.

From that point on, Oregon has struggled mightily in the face of any adversity.

When the Trojans started the third quarter on fire, the Ducks wilted.

When Washington State continually pinned Oregon’s once-potent offense deep in its own territory in the second half, the Ducks drowned.

And when the Huskies cashed in on two third-quarter turnovers within 20 yards of Oregon’s end zone last Saturday, the Ducks disappeared.

When the going has gotten tough the last month, Oregon has collapsed like Mike Tyson’s sparring partner.

After an unprecedented stretch of 33 wins in 36 games dating back to the middle of 1999, the Ducks have become afflicted by the here-we-go-again syndrome in dropping four of five.

The defense shouldered the blame against Arizona State, but the offense and special teams have been abysmal in the clutch the last two weeks (the offense was also atrocious during the fateful third quarter against USC).

"It’s called a team sport," senior defensive end Seth McEwen, a Medford native, said Saturday. "And that’s what this is about. Special teams, offense, defense — there’s no one thing that you can point out. You can’t point the finger because it’s a team sport. I play as a team; we play as a team here at Oregon."

Maybe the Ducks aren’t as good as they have been in recent seasons and feature just 11 seniors as high as second on their depth chart.

But Oregon has led in at least the second quarter in every defeat.

The fact is, the Ducks have lost their mojo.

And watching the last month’s downward spiral has been as ugly as a prolonged look at Austin Power’s teeth for Oregon fans.

"We’ve gotta focus forward — on Oregon State, on the Beavers, on the Civil War, on getting back on track," head coach Mike Bellotti said. "And just executing like we know we can for four full quarters."

Duck fans can only hope the team rediscovers its grit as well.

Otherwise, it could be a very painful Saturday at Reser Stadium in Corvallis.

Reach reporter Tim Pyle at 776-4483 or e-mail tpyle@mailtribune.com