Soccer-Arsenal go top after 0-0 draw with Middlesbrough

* Arsenal frustrated in 0-0 draw with Middlesbrough * Boro's Gaston Ramirez struck post with a free kick * Ramirez wasted two other great chances * Arsenal's Alexis Sanchez was denied by Victor Valdes save * Mesut Ozil had late goal disallowed * Arsenal at Sunderland next, Boro host Bournemouth ARSENAL 0 MIDDLESBROUGH 0 Oct 22 (Reuters) - Arsenal moved top of the Premier League table but were unconvincing in a 0-0 home draw with Middlesbrough who were well worth their point on Saturday. The Gunners dominated the opening 20 minutes but Boro should have led by halftime. Adama Traore broke clear but Petr Cech saved his shot with legs and Alvaro Negredo wasted a great chance from the rebound. The hosts had another let-off when Gaston Ramirez's curling free kick thumped against the post and Ramirez headed a great chance straight at Cech. Arsenal were better after the break and Boro keeper Victor Valdes made a superb save to keep out former Barcelona team mate Alexis Sanchez's dipping effort before Mesut Ozil had a late goal disallowed for offside. (Reporting by Martyn Herman, editing by Ed Osmond)