Arsenal endured a calamitous start to the Premier League season after conceding two penalties and having Laurent Koscielny dismissed in a 3-1 home defeat by Aston Villa on Saturday.
Christian Benteke, Villa's top scorer last season with 19 goals in his debut campaign, was the architect of Villa's shock win, scoring twice to puncture the pre-season optimism at the Emirates Stadium.
Olivier Giroud gave Arsenal a sixth-minute lead by clipping home a left-wing cross from Alex Oxlade-Chamberlain, but Benteke equalised in the 22nd minute.
Arsenal goalkeeper Wojciech Szczesny was penalised for tripping Gabriel Agbonlahor and although he redeemed himself by parrying Benteke's spot-kick, the Belgian striker reacted alertly to head in the rebound.
Benteke put Villa ahead from the spot with just under half an hour to play after Koscielny was adjudged to have fouled Agbonlahor, and the Frenchman's misery was compounded moments later when he was shown a second yellow card for an untidy lunge at Andreas Weimann.
Spanish close-season signing Antonio Luna completed victory for Paul Lambert's side with five minutes to play, running clear and coolly wrong-footing Szczesny.
Elsewhere, Roberto Martinez began his career as Everton manager by picking up a point from an entertaining 2-2 draw at Norwich City.
Quick-fire goals from Ross Barkley and Seamus Coleman put the visitors in front after Steven Whittaker had given Norwich the lead, only for £8.5 million ($13.3 million, 10 million euros) record signing Ricky van Wolfswinkel to equalise for the home side with a fine header in the 71st minute.
Rickie Lambert, who scored the winning goal against Scotland on his England debut in mid-week, completed a memorable few days by snatching a 1-0 win for Southampton at West Bromwich Albion with a last-minute penalty at the Hawthorns.
Meanwhile, Cardiff City made a disappointing return to the top flight following a 51-year absence after goals from Joe Cole and Kevin Nolan saw them beaten 2-0 at West Ham United, while a 52nd-minute header by Pajtim Kasami gave Fulham a 1-0 win at Sunderland.
Earlier, Simon Mignolet saved a last-gasp penalty to earn Liverpool a 1-0 win over Stoke City in the opening game of the new season at Anfield.
The Belgian goalkeeper, a £9 million signing from Sunderland, parried Jon Walters' 89th-minute spot-kick and then brilliantly blocked Kenwyne Jones' follow-up after Daniel Agger was penalised for handball.
The game, the first domestic league match in the world to be played with goal-line technology in place, was ultimately decided by a low 20-yard strike from Daniel Sturridge in the 37th minute.
Liverpool's fluid forward line of Sturridge, Philippe Coutinho and debutant Iago Aspas impressed in the absence of the suspended Luis Suarez, but it was Mignolet who proved the hosts' saviour.
"We bought him because he is a top, top goalkeeper and he had three saves to make in total," said Liverpool manager Brendan Rodgers.
"I thought overall our performance was outstanding."
Later on Saturday, David Moyes's reign as Manchester United manager will begin in earnest when the defending champions travel to Swansea City.
Moyes named Wayne Rooney on the substitutes' bench, after the unsettled striker made his first appearance of an injury-plagued pre-season in England's 3-2 victory over Scotland.