The Red Devils have been in brilliant form so far this season after having kicked off the new campaign in style under Jose Mourinho.
Manchester City signalled their title credentials last weekend when they beat Chelsea 1-0 at Stamford Bridge in impressive fashion.
Manchester United have won six of their opening seven Premier League games to leave them second in the table and level on points with leaders Manchester City.
Mourinho is aiming to become the first manager to steer Manchester United to the Premier League title since their final triumph under Sir Alex Ferguson in the 2012-13 campaign.
Former Manchester City boss Pearce believes that the title race will come down to a straight shootout between the two Manchester clubs – and he’s backing Mourinho’s men to come out on top.
Pearce told Yahoo! Sport: “I think the two Manchester clubs are going to be the ones to beat and, at the start of the season, I said United will win it – and I’ve seen no reason to change my mind.
“The only thing that might address the balance one way or another will be injuries to key players.”
Manchester United return to Premier League action after the international break with a crunch clash against Liverpool at Anfield on Saturday 14 October.
The Red Devils, who finished sixth under Mourinho in his first campaign last term, have also won their opening two Champions League group games this season.
MORE: Man United latest news
MORE: Arsenal latest news
MORE: Chelsea latest news
MORE: Liverpool latest news