By Simon Cambers NEW YORK, Aug 31 (Reuters) – Serena Williams will try to take another step toward a record-setting 23rd grand slam title at the U.S. Open on Thursday while Andy Murray continues his quest to complete a golden summer. World number one Williams faces fellow American Vania King in second round action and a victory would put her five match wins away from breaking the professional era record for grand slam titles that she currently shares with Steffi Graf. “I can improve a lot,” said Williams, who needed just 63 minutes to get by Russia’s Ekaterina Makarova in the first round.