Spain international Pedro scored on his debut game for Chelsea in their 3-2 away win at West Brom.
The new signing opened scoring for Jose Mourinho''s men as John Terry saw shown a red card.
Chelsea were lucky not to go behind all thanks to returning Thibaut Courtois who saved James Morrison's early penalty.
Pedro poked home his first Chelsea goal in the 20th minute before Diego Costa doubled the lead 10 minutes later.
Morrison atoned for his earlier penalty miss to pull a goal back five minutes later before Cesar Azpilicueta restored Chelsea's two-goal cushion in the 42nd minute.
John Terry, who was substituted for the first time ever under Jose Mourinho during last week's loss to Manchester City, was shown the red card bringing down Salomon Rondon.
Morrison added his second but the 10-men Chelsea held on to register their first win of the season.