كتب : وكالات
Florent Malouda opened the scoring after six minutes with a simple tap in after West Brom keeper Scott Carson failed to deal with a tame Drogba free kick.
Ivorian marksman Drogba doubled the lead shortly before the interval after slamming a right-footed free kick through the West Brom Wall and into the net.
He added the third in the 55th minute with a close-range finish before Frank Lampard put the result beyond doubt after rounding off a neat move eight minutes later.
Drogba, who finished as the Premier League top scorer last season, completed his hat-trick in the 68th minute via a 20-yard deflected shot.
Malouda scored his second of the night to complete the rout in the final minute.