If the Green Bay Packers go on to win their 14th NFL championship this season, their victory Sunday over the New England Patriots almost certainly will qualify as one of their biggest regular-season showdown victories ever. The only thing that might prevent it from cracking the top five would be if the Packers beat Detroit in an even bigger game Dec. 28.

The list here includes only late-season victories in the Packers' record 13 NFL championship seasons. That eliminated two of maybe the four biggest showdown games the Packers ever played.

One was their mid-November loss to the Chicago Bears in 1963 when both teams were 8-1. Vince Lombardi once said his 1963 team was his best ever, but it finished 11-2-1, a half-game behind the Bears and didn't play in the postseason. The other was the Packers' Thanksgiving Day loss to Detroit in 1962, but that year they still edged the Lions for the Western Conference title en route to winning Lombardi's second NFL title.

The Packers' last-second triumph over Chicago that decided the NFC North Division in the final game last season was certainly heartwarming, but doesn't make the list, either. It didn't lead to an NFL championship, always the ultimate goal of pro football's most storied franchise.

What games were considered for this list? Any game played over the second-half of a championship season that passed two litmus tests: Strength of the matchup and importance of the victory.

In the Packers' 94 seasons in the NFL, New England vs. Green Bay certainly ranks high on the list of late-season marquee matchups. This might have been as good as any in 50 years.

The Packers have been involved in late-season games where the combined records of the teams were better.

The Packers and Dallas, for example, were a combined 20-2 when they met Nov. 29, 2007. In early December 2004, Philadelphia and the Packers were a combined 17-5, the same as the Packers and Patriots entering Sunday's game. In 1998, Minnesota and Green Bay were a combined 16-4 entering a late November game.

But the Dallas game was the only one where the two teams were within one game of each other, just as the Patriots (9-2) and Packers (8-3) were before Sunday.

With Green Bay and New England playing in different conferences, the importance of Sunday's game wouldn't match the Packers' showdown with Baltimore in 1965, for example.

But, to that point, must-win games against conference and division foes have become somewhat rare in the age of expanded playoffs. For example, when the Packers beat AFC Central Division champ Pittsburgh on Christmas Eve 1995 on Yancey Thigpen's drop, it gave them their first division title in 23 years, but they had clinched a playoff spot the week before. The Packers also would lose in the NFC Championship Game that year.

So here's the list of the Packers' biggest late-season, regular-season showdown victories in their 13 championship seasons.

1. Packers 20, New York Giants 6 (Nov. 24, 1929, at Polo Grounds, New York) – If the Ice Bowl was the signature victory of the Lombardi Era, this was the signature victory of Curly Lambeau's 29 years as coach. It also led to the Packers' first-ever NFL title. They entered the game with a 9-0 record and a half-game lead over the 8-0-1 Giants at a time when the final standings determined the NFL champ. At season's end, the Packers won the title by that same half-game margin. They finished, 12-0-1; the Giants, 13-1-1. What was most notable about the victory was that 10 of the Packers' starters played 60 minutes and the 11th, guard Jim Bowdoin, played 59.

2. Packers 42, Baltimore Colts 27 (Dec. 12, 1965, at Memorial Stadium, Baltimore) – The game was played the second-to-last week of the season, and the 9-3 Packers trailed the 9-2-1 Colts by a half-game in the Western Conference. In other words if the Packers hadn't won, they would have been eliminated from the race at a time when only the conference champs qualified. Dave Robinson's 88-yard interception return and Paul Hornung's five touchdowns in a game played in a dense fog carried the Packers to a victory that served as the springboard for the first of Lombardi's record three straight titles from 1965-67.

3. Packers 45, New York Giants 17 (Dec. 26, 2010, at Lambeau Field) – The Bears had clinched the NFC North Division the week before and the Giants trailed Philadelphia in the NFC East by a game. Thus, this was a showdown for a Wild Card berth, and it turned out to be the win that put the Packers in the playoffs en route to winning Super Bowl XLV. Aaron Rodgers was as good in this victory as he was against the Patriots Sunday, throwing for 404 yards, four TDs and a 139.9 rating.

4. Packers 21, Chicago Bears 10 (Nov. 1, 1936, at Wrigley Field, Chicago) – This was the seventh game of a 12-game season. The Bears were 6-0, having beaten the 5-1 Packers, 30-3, in Week Two. After the Bears took a 10-0 lead in the first quarter, the Packers rallied behind fullback Clarke Hinkle, who rushed for 109 yards in 13 attempts and scored the go-ahead touchdown on a 59-yard run in the second quarter. At season's end, the Packers would edge the Bears by a game-and-a-half in the Western Division and then beat Boston for their first title under a playoff format. But reverse the outcome of this game and the Bears would have finished the regular season 10-2, leaving the 9-2-1 Packers out of the championship game.

5. Packers 20, New York Giants 17 (Dec. 3, 1961, at County Stadium, Milwaukee) – Both teams entered the game with 9-2 records. The Packers would go on to win the Western Conference by two-and-a-half games, but this was a preview of the 1961 NFL championship. Cornerback Jesse Whittenton stole the ball from Alex Webster to set up the Packers' winning touchdown in the fourth quarter and also held all-pro receiver Del Shofner to one catch. Despite losing this game, the Giants won the Eastern Conference by a half-game over defending NFL champ Philadelphia and then lost to the Packers, 37-0, in the NFL title game.