Manchester United began its Premier League title defense with a convincing 4-1 win at Swansea City on Saturday while Arsenal endured a dismal start to the season after a shock 3-1 home defeat by Aston Villa.
Robin van Persie and Danny Welbeck scored two goals each to give David Moyes a winning start to his reign as United manager in driving rain at Swansea's Liberty Stadium.
Villa striker Christian Benteke was the scourge of Arsenal with two goals at a hushed Emirates Stadium where the hosts took an early lead and finished the game with 10 men after Laurent Koscielny was sent off.
Liverpool striker Daniel Sturridge scored and new goalkeeper Simon Mignolet saved a late penalty to earn their side a deserved 1-0 win over Stoke City in the early kickoff at Anfield while West Ham United beat promoted Cardiff City 2-0.
Van Persie put United ahead after 34 minutes against Swansea, hooking home a bouncing ball from eight meters. Welbeck doubled the lead with a tap-in, Van Persie lashed in his second 18 minutes from time and, after Wilfried Bony pulled one back, Welbeck completed the rout with a delightful chip from a narrow angle.
"We are very happy," Van Persie told Sky Sports. "To play against Swansea away from home is tough.
"I love the way they play but it's hard to play against. Swansea were better than us for the first 20 minutes or so but the goal changed the game.
Arsenal went ahead against Villa after six minutes through a neat finish by forward Olivier Giroud but that was as good as it got for the hosts.
Benteke netted the rebound after having a penalty saved and then made no mistake from the spot after 62 minutes to put Villa 2-1 up.
Koscielny was sent off for his second bookable offense and, with disgruntled Arsenal fans leaving the ground, Antonio Luna added Villa's third.
"We started well but after that everything went wrong - injuries, decisions, going down to 10 men and the chances missed," Wenger told reporters. "It was a bad day, not on the quality of our display but everything went against us.
"What hurts me is to disappoint people who love the club. All the rest I have to live with but I'm here to make people happy and when I do not I can only say sorry and come back and make them happy in the next game."
Villa manager Paul Lambert waxed lyrical about the performance of forward Gabriel Agbonlahor.
"After weathering the early storm we were outstanding especially on the counter-attack," Lambert said.
"We were absolutely frightening at times - Gabriel Agbonlahor produced as good a performance as I've seen in many a year, he was unplayable. We were well worthy of winning the game."
Sturridge put Liverpool ahead against Stoke with a firm 20-metre shot after 37 minutes and the hosts dominated a frenetic match, only to be denied a second by a brilliant goalkeeping display from Stoke's Asmir Begovic.
The visitors threatened occasionally on the break and were awarded a penalty when Liverpool defender Daniel Agger needlessly handled a long Charlie Adam free kick.
But Mignolet, who had endured a nervous debut, palmed away a weak effort from the spot by Jonathan Walters a minute from time to spark wild celebrations around the ground.
Joe Cole scored an early goal for West Ham and fellow midfielder Kevin Nolan added a late second to hand Welsh side Cardiff a losing start in their first top-flight season since 1962.
Norwich City and Everton drew 2-2 in an entertaining match at Carrow Road where, after a goalless first half, defender Steven Whittaker put the home side ahead before the visitors equalised with a superb shot by 19-year-old midfielder Ross Barkley.
Southampton striker Rickie Lambert, who scored a late winner for England against Scotland on Wednesday, converted a last-minute penalty to seal a 1-0 win at West Bromwich Albion.
Fulham won 1-0 at Sunderland thanks to a 52nd-minute header by midfielder Pajtim Kasami, his first goal for the club.