Khazri then broke on the left before switching the line of attack with a delightful delivery to skipper Lee Cattermole, who was foiled by Foster. After the break, Jan
Kirchhoff forced his way through after good work by Fabio Borini to bring a point-blank stop from Foster.
Gareth McAuley then blocked Defoe’s shot and Borini’s drive was beaten away by Foster.
Borini was out of luck again as he swept DeAndre Yedlin’s cross wide. Kirchhoff then made a last-ditch challenge to deny Salomon Rondon before Borini had Foster at full stretch with a stinging effort.
West Brom boss Tony Pulis said: “I’m doing somersaults! To get to 40 points with seven games to go is first class.”