Didier Drogba scored a hat-trick as Chelsea signalled their intent to defend their Premier League title by thrashing newly-promoted West Brom.
Florent Malouda struck early on from six yards before Drogba scored with a free-kick on the stroke of half-time.
Drogba later pounced after a goal-line clearance and scored with a deflected strike from the edge of the area.
Frank Lampard finished an attractive move, while Malouda struck from close range on the stroke of full-time.
Chelsea, who ended last season with an 8-0 thrashing of Wigan, have now won the opening day for the last nine seasons.
And they move instantly to the top of the table after the biggest opening day victory in the history of the Premier League.
Chelsea manager Carlo Ancelotti saw his champions play with a confidence, skill and composure that seemingly enabled them to slice open their opponents at will.
It was a chastening afternoon for West Brom and their manager Roberto di Matteo, a former Chelsea player who received a generous reception from the Stamford Bridge crowd.
