LONDON Serena Williams claimed a sixth Wimbledon title and fourth successive grand slam crown by suppressing the spirited attacking instincts of 20th-seeded Spaniard Garbine Muguruza to win Saturday’s final 6-4 6-4. American Williams reinforced her stranglehold on the women’s game by overcoming an early wobble and resisting a battling fightback to claim a 21st grand slam title that leaves her one behind German Steffi Graf’s record haul of professional era majors