HALLE WESTFALEN:- Roger Federer stepped up his grass game as the start of Wimbledon looms, holding off Australian Matt Ebden 7-6 (7/2), 7-5 in their quarter-final at the ATP Hale tournament on Friday. With his world number one ranking on the line, the Swiss is sparing no effort to make sure he lifts a tenth title at the event on Sunday. Failure to win the grass title would send rival Rafael Nadal back to the top spot. Federer will next take on qualifier Denis Kudla, who scored the best grass victory of his career as he beat Japan's Yuichi Sugita 6-2, 7-5.