Ben Arfa opened the scoring from close range in the 18th minute and then, after Christian Benteke's headed equaliser in the 67th, drilled a 73rd-minute shot which was parried by Brad Guzan, who saw substitute Yoan Gouffran arrive in space to convert the loose ball.
The manager said of Ben Arfa: "He was brilliant.
"I think people will have been thrilled by him today.
"He was magnificent, unplayable really.
"I thought the (positive) reaction (from other people) to his performance last time was slightly over the top, but I don't think it can be this week.
"He really was very, very good."
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