Teenage striker Anthony Martial further endeared himself to Manchester United’s supporters with a nerveless brace as his side came from behind to win 3-2 at Southampton on Sunday. Scorer of a memorable solo goal in last weekend’s 3-1 win over Liverpool, 19-year-old Martial struck either side of half-time at St Mary’s after Graziano Pelle had given Southampton a 13th-minute lead. Juan Mata added a third in the 68th minute and despite Pelle scoring again, United held on for a victory that propelled Louis van Gaal’s side up to second place in the Premier League table, two points below leaders Manchester City, who lost 2-1 at home to West Ham United on Saturday. Read all our English Premier League coverage here A lot of people are thinking he is a great star, but he is a boy of 19 Louis van Gaal “Anthony Martial is already special because we paid a lot of money for him,” Van Gaal said. “A lot of people are thinking he is a great star, but he is a boy of 19. In three matches he has shown a lot. “I am very happy with him, but we and he have to keep our feet on the ground.” Martial, who signed from Monaco on transfer deadline day for a reported initial fee of £36 million (HK$433 million), started up front alongside Wayne Rooney, who returned following a hamstring injury. Southampton went ahead when Pelle followed in to score after Sadio Mane’s shot from James Ward-Prowse’s inviting right-wing cross had been parried by visiting goalkeeper David de Gea. Pelle hit the post moments later, but Martial equalised in the 34th minute, throwing Virgil van Dijk off balance with a neat Cruyff turn inside the box and slipping a shot beneath Maarten Stekelenburg. He put United ahead five minutes into the second half, seizing on a woeful Maya Yoshida back-pass and coolly beating Stekelenburg, before Mata slammed home after Memphis Depay’s shot came back off the post following a hypnotic 44-pass move. While Martial again stole the headlines, United were also indebted to De Gea, who produced a jaw-dropping one-handed save to claw a Jose Fonte header off the line when the score was 2-1. Pelle converted a cross from Mane with a well-placed header four minutes from time, but United survived.