Leicester became the first reigning Premier League champions to lose their opening game as they suffered a 2-1 defeat at Hull.
The newly-promoted Tigers had suffered a chaotic summer in losing manager Steve Bruce and supporters protesting at the Allam family's ownership of the club.
Injuries had left caretaker boss Mike Phelan with only 13 senior players in his squad, but Hull somehow overcame the odds to stun Claudio Ranieri's champions.
Goals from Adama Diomande and Robert Snodgrass gave Hull a 2-1 victory over the defending champions. Riyad Mahrez scored a penalty from the spot.
In the other matches for the day, Ronald Koeman era at Everton began with a 1-1 draw against Tottenham. Stoke City also fought back to draw 1-1 at Premier League new boys Middlesbrough.
Leroy Fer's first Swansea goal gave the Welsh club a 1-0 win at promoted Burnley.
Fer made his loan switch from QPR permanent in the summer and he celebrated by pouncing on a rebound eight minutes from time.
West Brom boss Tony Pulis enjoyed a 1-0 win at former club Crystal Palace.
It was a game of few chances, but Salomon Rondon's glancing header from James McClean's 74th-minute cross settled matters.
The final game of the day saw Manchester City win 2-1 over Sunderland. Pep Guardiola's first match in charge was a cagey one.
Guardiola had made an immediate impact at City by dropping Joe Hart and Yaya Toure and on the field his side quickly took the lead with a Sergio Aguero penalty.