The Saints were forced to play almost the whole of the second period with 10 men but still managed to claim all three points against Slaven Bilic's in-form Hammers.
Southampton secured its first win in four games with a 1-0 win over West Ham at St. Mary’s Stadium on Saturday.
Maya Yoshida made the difference after nine minutes on the south coast, as he sidefooted past Adrian after collecting Victor Wanyama's stabbed ball into the area following Saido Mane's tucked inside pass.
With 28 minutes on the clock Fraser Forster pulled off a magnificent save to prevent Winston Reid from close range, swatting his powerful header away from goal.