كتب : Hatem Maher
Debutant Peter Odemwingie scored the winner nine minutes from time as West Bromwich secured a deserved victory to make up for a humiliating 6-0 defeat by holders Chelsea in their first league game.
The Nigerian striker, who joined West Bromwich from Lokomotiv Moscow, poked home after latching onto a pass from James Morrison.
Egyptian winger Elmohamady was included in Sunderland's starting line-up for the second successive game.
He played on the right side of a four-man midfield but wasn't as lively as he was in the opening 2-2 draw with Birmingham City.
Elmohamady's best effort came after 25 minutes when he skipped past his challenger down the right before pulling the ball back to Cristian Riveros, whose shot was blocked by a defender.
The Egyptian international also whipped in a cross on the stroke of halftime but it went begging.
Elmohamady, who joined Sunderland from Egyptian Premier League side ENPPI on a season-long loan, was replaced with Danny Welbeck in the 76th minute.
Sunderland hardly created any goalscoring chances to lose to a spirited West Brom side.