memphis grizzles ' defence helped them to a 100-92 win over oklahoma city .
they moved level with houston rockets at top of the southwest division .
thunder star russell westbrook was largely shut down in their defeat .
san antonio stayed within two games of fight over no 2 playoff seed .
spurs cruised past denver 123-93 after losing tiago splitter to a calf injury .
brooklyn 's deron williams scored 31 to lead the nets to a 114-109 win .