Manchester United’s Ander Herrera and Paul Pogba headed first-half goals to claim a 2-0 win that dumped FA Cup holders Chelsea out of the competition and secured a place in the quarterfinals in an intense tie at Stamford Bridge on Monday. Spaniard Herrera finished off a fine move with a precise header from Pogba’s cross just past the half-hour and United’s French midfielder scored himself when he nodded powerfully home from a Marcus Rashford delivery before the break.