​Both the Arizona Cardinals and Philadelphia Eagles now have a 2-4 record [Getty Images]Week six in the NFL produced some unlikely heroes as the Arizona Cardinals pulled off the biggest upset of the season so far.Kicker Chad Ryland scored all of Arizona’s points at the Los Angeles Rams to leave the former Super Bowl favourites bottom of the NFC West division.The Philadelphia Eagles continued to struggle but their former Super Bowl rivals the Kansas City Chiefs remained unbeaten.The Cleveland Browns maintained their surprise start while the Houston Texans concluded this year’s London series by winning a thriller at Wembley.Here are five things you need to know from Sunday’s action.Rams need to stop the rotThe Los Angeles Rams started the season as the clearest Super Bowl favourites in nine years but were replaced by the San Francisco 49ers after last Monday’s overtime defeat by the Buffalo Bills.They cut kicker Harrison Mevis on Tuesday and signed Blake Grupe from the New York Jets’ practice squad, and although Grupe’s field goal opened the scoring against Arizona, he injured a knee while making a tackle from the ensuing kick-off.The Rams edged back in front with 47 seconds remaining as punter Ethan Evans took on the kicking duties to add the extra point after Colby Parkinson’s touchdown.But Arizona hit straight back and a career-high sixth field goal by Chad Ryland clinched an 18-16 win as time expired.After just three wins last season, the Cardinals now have two this year and both have come at SoFi Stadium having also beaten the Los Angeles Chargers in week one.Arizona also crept above the Rams in a division which features the unbeaten 49ers and defending champions the Seattle Seahawks.”We’ve got to be able to figure it out and it starts with me,” said the Rams’ head coach Sean McVay.Walker continues to set paceKenneth Walker (centre) is arguably the first elite running back Patrick Mahomes has had at his disposal during his 10-year NFL career [Getty Images]Kansas City Chiefs quarterback Patrick Mahomes reached 100 regular-season wins in his 131st start, tying Tom Brady’s record.After missing out on last season’s play-offs, the Chiefs boosted their roster by signing the Super Bowl’s Most Valuable Player Kenneth Walker and he rushed for another 128 yards and two touchdowns in Sunday’s 22-6 win over the Chargers.The running back now leads the NFL with 665 rushing yards, a record from a player’s first five games with a new team, and the Chiefs visit his former team Seattle next Sunday.Kansas City and the Minnesota Vikings are now 5-0 while San Francisco – the only other unbeaten team after five wins – are at home to Washington on Monday night.The Buffalo Bills held on for a 33-30 win at the Las Vegas Raiders to improve to 5-1 while Caleb Williams returned from a hamstring injury to help the Chicago Bears to a 31-23 win at the Atlanta Falcons.Eagles begin Hurts absence with lossThe Philadelphia Eagles were already struggling with injuries before last