Osaze Odemwingie scored for the Baggies
The Brendan Rodgers era at Liverpool got off to a disappointing start as they lost 3-0 at West Brom.
Zoltan Gera gave the hosts the lead just before the break with a stunning long-range strike, reports the BBC.
Daniel Agger was sent off 12 minutes into the second half but Shane Long missed the resulting penalty.
However, Peter Odemwingie made no mistake from the spot in the 67th minute before substitute Romelu Lukaku added a third.
And at Loftus Road, Michu and Nathan Dyer both scored twice to help Michael Laudrup get off to an impressive start as Swansea boss with a thumping victory over home side, QPR.
A disastrous defensive display by Rangers began when Rob Green could not stop Michu's speculative 25-yard shot.
Swansea hit the bar twice before Michu curled home his second after the break.
QPR crumbled completely by the end, with Nathan Dyer scoring twice in quick succession before Scott Sinclair completed the rout with a low finish.
The Welsh side put on a passing performance reminiscent of their best form under previous boss Brendan Rodgers, in what will go down as a perfect Premier League bow for their new Danish manager.
But the day was a horrific case of déjà vu for QPR fans, who saw their side collapse to a comprehensive opening day defeat against Bolton at Loftus Road last August.
Things were meant to be different this time, with Rangers boss Mark Hughes fielding a raft of summer signings and promising there would be no repeat of the relegation struggle which his side only just survived.
However, at the Emirates, fans left unhappy after Arsenal could only manage a goalless draw against Sunderland.
Their day could not get any worse with news filtering in that Alex Song is Barcelona bound after the Gunners accepted a fee reported to be in the region of £19million for the Cameroon international.
In other matches, Fulham also ran away 5-0 winners over Norwich, Reading played 1-1 with Stoke and newly promoted West Ham got the better of Aston Villa 1-0.