As the 2026 NFL regular season reached its fourth week, the league’s crop of unbeaten teams shrank dramatically, leaving just three squads still holding perfect 4-0 records after a day of thrilling, momentum-shifting matchups across the country. The week’s action kicked off with the first of this season’s three scheduled London games, where the Indianapolis Colts secured a win over the Washington Commanders to open Sunday’s slate. Among the standout storylines of the day were dramatic upset wins, career-defining individual performances, and late-game twists that reshaped early-season title narratives.
Five teams entered Week 4 with undefeated 3-0 records, but only three walked away with their winning streaks intact. The first of those matchups pitted division rivals the Kansas City Chiefs and Las Vegas Raiders against one another, guaranteeing at least one unbeaten would fall. Las Vegas, which only notched three total wins last season, has been a vastly improved side in 2026, and they pushed the reigning contenders all the way to the final whistle. The Raiders held a 13-10 lead entering the fourth quarter, with three lead changes swinging the game back and forth before the Chiefs held on for a narrow 30-27 victory.
The game’s turning point came in a chaotic 19-second stretch, where new Chiefs running back Kenneth Walker—who has enjoyed a breakout start to his 2026 campaign—scored two touchdowns, with Kansas City immediately forcing a fumble on the ensuing kickoff return to regain possession. The Raiders clawed back to within striking distance after a score from Brock Bowers, and stayed in the game until its final play: a pass from newly acquired quarterback Kirk Cousins was intercepted as he was tackled mid-throw, sealing the Chiefs’ undefeated run. Walker finished the game with an impressive 177 yards on 22 carries, while teammate Tyquan Thornton added two receiving touchdowns and 111 yards through the air. Fresh off missing the 2025 playoffs, the Chiefs now look like legitimate Super Bowl contenders, and they will next face the winless Los Angeles Chargers, who fell to 0-4 after a 30-23 loss to defending champions the Seattle Seahawks.
The other two undefeated teams to punch their tickets to 4-0 are the San Francisco 49ers and the Minnesota Vikings, the latter of which has emerged as the biggest early-season surprise of the league. The 49ers hosted the Denver Broncos, who pulled off a major upset over Super Bowl favorite Los Angeles Rams just one week prior. The game remained deadlocked at 3-3 late into the third quarter, before a fourth-quarter rushing touchdown from Christian McCaffrey gave San Francisco breathing room. Though the Broncos responded with a score from Jaylen Waddle, a long catch-and-run touchdown from George Kittle sealed a 24-14 win for the 49ers. Quarterback Brock Purdy has continued his impressive form, tying Cousins for the league lead with 11 touchdown passes through four games, while only throwing one interception and avoiding being sacked once all season.
Minnesota, meanwhile, ground out a low-scoring 15-10 win over the Miami Dolphins, kicking five field goals from kicker Will Reichard to secure their fourth consecutive win, defying pre-season expectations that projected the Vikings to finish near the bottom of their division.
One of the most unexpected upset victories of the day came from the New England Patriots, who traveled to face the undefeated Buffalo Bills led by 2024 MVP Josh Allen. Second-year quarterback Drake Maye had entered the game under intense scrutiny: after throwing just eight interceptions throughout the entire 2025 regular season (when he led the Patriots to an unlikely Super Bowl run and narrowly lost MVP voting to Rams quarterback Matt Stafford), Maye had thrown six interceptions and only one touchdown through the Patriots’ first three games of 2026, and was benched in a blowout loss to Jacksonville the prior week, leading many pundits to question his confidence. Maye silenced his critics on Sunday, throwing for 269 yards and three touchdowns. After Allen put the Bills back ahead with a 34-yard touchdown pass with just four minutes left to play, Maye led a game-winning drive that ended in a sensational one-handed endzone touchdown catch from Efton Chism, putting New England up 29-26. The Patriots clinched the upset with a late interception of Allen, dropping the Bills to 3-1.
The Los Angeles Rams also pulled off a dramatic road comeback win over the Philadelphia Eagles to avoid falling to 1-3 on the season. The Eagles led 20-10 at halftime thanks to two first-half touchdowns from Darius Cooper, but the Rams rallied late, with running back Kyren Williams rushing for two touchdowns in the final four minutes to secure a 24-20 come-from-behind victory. A key factor in the Eagles’ loss was mounting injury issues: star wide receiver DeVonta Smith missed the game with a hamstring injury, joining tight end Dallas Goedert on the sidelines, and star running back Saquon Barkley left the game early with a hamstring injury. The injury crisis comes at a bad time for the Eagles, who are set to play the Jacksonville Jaguars at London’s Tottenham Hotspur Stadium next Sunday. Jacksonville improved to 3-1 on Sunday with a 22-17 win over the Cincinnati Bengals, notching their second consecutive victory. The Baltimore Ravens also notched a 24-18 home win over the Tennessee Titans, though they are now dealing with their own key injury concern after two-time MVP Lamar Jackson was sidelined for the entire second half with an ankle injury.
In a matchup of Texas rivals, the Dallas Cowboys pulled off a late game-winning drive to beat the Houston Texans 34-30. All of Dallas’s games this season have featured at least 48 total points, and Sunday’s showdown was no exception: the Texans held a 23-13 lead in the third quarter and extended their advantage to 30-27 with just two minutes left to play. Cowboys quarterback Dak Prescott led an 11-play, 74-yard game-winning drive, capped off with a touchdown pass to star wide receiver CeeDee Lamb, who now leads the entire league in receiving yards with 494 yards through four games. Lamb notched a career-high 17 receptions for 189 yards in the win, while Cowboys running back Javonte Williams added three rushing touchdowns to lift Dallas to a 2-2 record on the season.
The highest-scoring game of Sunday came in East Rutherford, where the New York Giants beat the Arizona Cardinals 36-24. Veteran backup quarterback Jameis Winston, filling in for injured starter Jaxson Dart, threw three touchdowns and two interceptions to secure the win for the Giants.