Darnold, the revelation of the season so far, threw for 275 yards and three touchdowns at Lambeau Field as Minnesota moved to 4-0 on the season -- their best start in eight years. Super Bowl champions Kansas City ground out their fourth straight win, a 17-10 victory at the Los Angeles Chargers. But the Pittsburgh Steelers suffered their first defeat of the season with a 27-24 loss to the Indianapolis Colts and their 39-year-old stand-in quarterback Joe Flacco. The Vikings broke out to an early 14-0 lead thanks to Darnold finding Jordan Addison with a 29-yeard touchdown pass and then connecting with Josh Oliver on a two-yard pass at the end of the first quarter. Minnesota continued to dominate in the second quarter, with Addison rushing in from seven yards and then Darnold finding his favourite target Justin Jefferson with a 14-yard pass to make it 28-0. But the Packers gave themselves a lifeline at the end of the half when Jayden Reed collected a 15-yard pass from Love to reduce the deficit. The Packers came roaring back in the fourth quarter with Love throwing touchdowns to Dontayvion Wicks and Tucker Kraft to cut the lead to six points. A 33-yard Will Reichard field goal for the Vikings made it a two-score lead, however, and although Love found Wicks for another touchdown the attempted onside kick was taken care of by the Vikings and they held on for the win. "We believe in each other more than anyone else believes in us, we have a really good formula but we need to learn and grow," said Darnold, reflecting on how they had let Green Bay back into the game in the second half. Packers quarterback Jordan Love threw four touchdowns and put up 389 yards but he was also intercepted three times as the Packers fell to 2-2. The Chiefs made a slow start in Los Angeles and trailed 10-0 until with four minutes left in the half, quarterback Patrick Mahomes threw a monster 54-yard pass to Xavier Worthy in the end zone. A 37-yard Harrison Butker field goal tied the game in the third and the Chiefs secured the win with Samaje Perine finishing off a 5 play, 60-yard drive with a 2-yard rush up the middle.   - Flacco returns - Flacco made yet another return to the NFL, coming on for injured Indianapolis quarterback Anthony Richardson and throwing two touchdowns as the Colts handed divisional rivals the Steelers their first loss. Flacco, who was awarded the Comeback Player of the Year last season for his efforts with Cleveland, came in during the first quarter and his four-yard pass to Josh Downs put the Colts 14-0 up. His 15-yard pass to Drew Ogletree at the start of the fourth gave the Colts a 24-10 lead but a 2-yard rushing touchdown from Steelers quarterback Justin Fields made it tight at the end. The Colts are the third team in the AFC North that Flacco has played for after his spells with Baltimore and the Browns. The Philadelphia Eagles fell to 2-2 after a 33-16 defeat to the Tampa Bay Buccaneers with Baker Mayfield throwing for two touchdowns and 347 yards and also running in a score. Youngheo Koo's 58-yard field goal with two seconds remaining earned the Atlanta Falcons a 26-24 win over NFC South rivals the New Orleans Saints. The Falcons won without an offensive touchdown -- a KhaDarel Hodge fumble return in the endzone opened the scoring in the first and a 47-yard interception return from Troy Anderson had given the Falcons a 17-4 lead at the half. The unbeaten Buffalo Bills face the Baltimore Ravens later on Sunday.