Promoted Bournemouth and Yeovil Town also picked up three points, but Doncaster Rovers were beaten at home by Blackpool.
Leeds United secured a dramatic win over Brighton & Hove Albion, Nottingham Forest edged out Huddersfield Town and there was a derby stalemate at Turf Moor.
Watford picked up a narrow win at Birmingham City and Leicester City overturned a half-time deficit to claim the points at Middlesbrough.
Nedum Onuoha and Andrew Johnson scored just before half-time as promotion favourites QPR came from behind to beat Sheffield Wednesday 2-1 at Loftus Road.
Reading also recovered from conceding an early goal to win 2-1 at home against Ipswich Town, with Danny Guthrie's 75th minute effort proving the difference.
New signings Grant Holt and Leon Barnett were among the scorers as Wigan romped to a 4-0 win at Barnsley, who saw Dale Jennings sent off on his debut.
Ed Upson scored with two minutes left to hand Yeovil a memorable 1-0 win at Millwall in the club's first match in the Championship.
Bournemouth marked their return to the second tier with victory as Lewis Grabban scored a goal in each half in a 2-1 home triumph over Charlton Athletic.
But Doncaster failed to emulate their fellow promoted clubs as Tom Ince's last-minute goal wrapped up a 3-1 win for Blackpool at the Keepmoat Stadium.
New signing Luke Murphy quickly endeared himself to the Elland Road faithful as he scored a 94th minute winner as Leeds beat Brighton 2-1.
Troy Deeney is among the favourites to be the division's top scorer and his 11th minute goal earned Watford a 1-0 win at Birmingham.
Forest were also 1-0 winners as Billy Davies' likely promotion contenders beat Huddersfield thanks to Henri Lansbury's 53rd minute goal.
Burnley and Bolton Wanderers got the Championship season up and running at lunchtime, and Darren Pratley's equaliser secured the visitors a 1-1 draw in the local derby at Turf Moor.
Goals from Danny Drinkwater and Jamie Vardy in the space of seven second-half minutes gave Leicester a 2-1 success at Middlesbrough.