Sir Alex Ferguson believes Wayne Rooney can surpass Cristiano Ronaldo's 42-goal haul after the England striker steered Manchester United to the Champions League quarter-finals. Rooney repeated his double against AC Milan to help United win 4-0 on Wednesday, making it four goals over the two last 16 legs. The on-fire striker also reached the 30-goal mark in all competitions with the English champions. "It's a challenge (for Rooney to reach Ronaldo's tally). I was happy with him getting to the 30 mark, to be honest," said Ferguson after the game. "But he just keeps improving and tonight he was sensational." Complete After seeing his side undone by the Red Devils, Milan manager Leonardo has also heaped praise on the man who was responsible for most of the damage. "I think this year Rooney can grow up even more. He's the complete player; strong, fast and he works hard," the Brazilian said. "He does a lot of incredible movement and he's playing in a system that is perfect for him. "United play at such speed and often on the counter-attack. That system, with Rooney, is incredible." United 4-0 Milan