It was Theo Walcott.
Darren Fletcher has yet to score a career hatrick. However did score a brace againt Arsenal in the 2008 FA Cup.
yes and they won 6-0
Dwight Yorke. Roy Keane, Ole Gunnar Solskjaer and Teddy Sheringham scored the others for United, whilst Thierry Henry scored Arsenal's consolation.
The most recent scorer on his debut was Samir Nasri, 228 seconds into the game against West Brom. Marouane Chamakh also scored on his home debut against Blackpool
Alan Ball. Blackpool, Everton, Arsenal, Southampton
Wayne Rooney in Man Utd's 8-2 Victory against Arsenal
Thierry scored ten goals against Chelsea in all competitions for Arsenal.
wins for arsenal against man utd october 23rd 1997 7-0 to arsenal against utd march 9th 1999 6-3 to arsenal April 12th 1999 6-1 to arsenal may 29th 2000 2-1 to arsenal November 9th 2001 2-0 to arsenal 16th December 2001 5-2 to arsenal 12th march 2002 6-1 to arsenal 18th April 2005 5-0 to arsenal
against tottenham
Cest Fabregas' debut with Arsenal was against Rotherham United on October 23, 2003.
I think it was Gilberto Silva who scored for Arsenal against PSV Eindhoven in the Champions League.
6-0