They have now completed the journey to the top spot from the No. 32 ranking they held before Alex Smith's first game as a rookie in 2005.
The 49ers are now 15-3 during the regular season under Jim Harbaugh after claiming 14 total victories over the 2009 and 2010 seasons combined.
Of course, we knew the 49ers would be good this season. They opened the regular season at No. 5. Few expected the Arizona Cardinals to keep pace with them in the standings through the first two games, particularly with New England on the schedule. The Cardinals, coming off a 20-18 road shocker over the Patriots, now have a 7-1 record over their past eight games. They won seven of their final nine last season and have ridden a dominant defense to a 2-0 record in 2012.
One of our five Power Rankings panelists, Jamison Hensley, bucked perception by making the Cardinals his preseason pick to win the NFC West.
What was he thinking?
"There are always teams in the NFL that finish strong the season before and carry that over into the following year," he said Tuesday. "The Cardinals are a classic example of that after winning seven of their last nine in 2011."
"I've always considered Ken Whisenhunt to be among the most underrated coaches in the league," Hensley said. "That's why I picked Arizona as the surprise winner of the NFC West and that's why I'm not surprised by their strong start. Of course, I can't really gloat. The 49ers have been the best team in the NFL so far."
And now, a closer look at the rankings for this week:
Falling (15): Kansas City Chiefs (-9), New Orleans Saints (-8), Dallas Cowboys (-5), Washington Redskins (-5), Oakland Raiders (-5), New England Patriots (-4), Chicago Bears (-4), Tennessee Titans (-4), Baltimore Ravens (-3), Jacksonville Jaguars (-2), New York Giants (-1), Denver Broncos (-1), New York Jets (-1), Minnesota Vikings (-1), Cleveland Browns (-1).
Rising (15): Seattle Seahawks (+9), Arizona Cardinals (+6), Philadelphia Eagles (+5), Miami Dolphins (+5), Indianapolis Colts (+5), Carolina Panthers (+4), St. Louis Rams (+4), Atlanta Falcons (+3), San Diego Chargers (+3), Houston Texans (+2), Pittsburgh Steelers (+2), Cincinnati Bengals (+2), Buffalo Bills (+2), San Francisco 49ers (+1), Green Bay Packers (+1).
Deadlocked: We broke two ties this week. Arizona prevailed over Dallas at No. 14 on the second tiebreaker, overall record. Seattle prevailed over the New York Jets at No. 17 based on the third tiebreaker, which team won a game most recently.
Like minds: All five panelists voted the 49ers No. 1. One spot separated high and low votes for the Texans, Falcons and Jaguars.
Agree to disagree: Seven teams generated disparities of six spots between high and low votes.
A look at the teams generating high-low disparities of at least six spots in the rankings:
Panthers (7): Ashley Fox ranked them 16th, higher than any other voter ranked them. Dan Graziano ranked them 23rd, lower than any other voter ranked them.
Redskins (7): Graziano 16th, John Clayton and Hensley 23rd.
Giants (6): Fox fifth, Clayton 11th.
Bengals (6): Clayton 15th, Fox 21st.
Buccaneers (6): Clayton and Hensley 19th, Fox 25th.
Saints (6): Graziano 18th, Clayton and Hensley 24th.
Chiefs (6): Graziano 25th, Hensley 31st.
Power Rankings histories: These colorful layered graphs show where each NFL team has ranked every week since the 2002 season.
Ranking the divisions: Teams from the NFC East ranked 12.2 overall on average, best for any division. Teams from the NFC West averaged 13.6, which ranked second. The NFC North was third with a 14.4 average.
Our divisional bloggers on the panel -- Graziano (NFC East), Hensley (AFC North) and me (NFC West) -- continued to rank teams from our divisions higher than the other panelists ranked them. Graziano had a 10.5 average for the NFC East, two spots higher than any other panelist on average. Hensley ranked AFC North teams at 15.5 on average, slightly higher than Clayton ranked them (15.75). I ranked NFC West teams at 12.25 on average, higher than anyone else ranked them (Hensley 12.75).
A voter-by-voter look at changes of at least five spots since last week:
Sando: Chiefs (-11), Saints (-9), Bears (-6), Redskins (-6), Cowboys (-5), Chargers (+5), Cardinals (+6), Eagles (+7), Seahawks (+7), Rams (+8).
Clayton: Chiefs (-9), Saints (-9), Redskins (-9), Titans (-7), Raiders (-6), Colts (+5), Rams (+5), Cardinals (+8), Seahawks (+8).
Graziano: Chiefs (-8), Cardinals (+6), Dolphins (+6), Seahawks (+8).
Hensley: Raiders (-9), Saints (-8), Redskins (-8), Cowboys (-7), Chiefs (-7), Patriots (-7), Cardinals (+6), Colts (+6), Falcons (+7), Rams (+7), Seahawks (+10).
Fox: Chiefs (-8), Saints (-8), Patriots (-6), Titans (-6), Bears (-5), Bills (+5), Seahawks (+5), Falcons (+6), Cardinals (+7).
For download: An Excel file -- available here -- showing how each voter voted this week and in past weeks.
The file includes a "powerflaws" sheet pointing out potential flaws in voters' thinking by showing how many higher-ranked opponents each team defeated this season.
For example, the Eagles rank lower than the Ravens even though Philadelphia defeated Baltimore in Week 2.
A quick primer on the "powerflaws" sheet:
Column Y features team rankings.
Column Z shows how many times a team has defeated higher-ranked teams.
Change the rankings in Column Y as you see fit.
Re-sort Column Y in ascending order (1 to 32) using the standard Excel pull-down menu atop the column.
The information in Column Z, which reflects potential ranking errors, will change (with the adjusted total highlighted in yellow atop the column).
The lower the figure in that yellow box, the fewer conflicts.