Sandwiched between Andy Pettitte’s retirement announcement Friday and Mariano Rivera’s sendoff party Sunday the Yankees faced the minor detail of desperately needing to win another game Saturday at the Stadium. Keeping their faint playoff hopes alive yet again the Yanks secured their second straight victory from the out-of-it Giants 6-0 behind a stellar bounce-back performance by Ivan Nova — his second shutout in five starts. “It means a lot. I know we need to win games and it’s no time to pitch the way I pitched the time before (Sunday in Boston)” Nova said. “Every time you go out there you hope to have a good game. If you have a complete game it’s a great feeling especially for the time of the year that we are. “You are pretty much a little tired at this time and the race that we have you want to win and to give your bullpen a day off is really important for us.” Eduardo Nunez and Alfonso Soriano homered and Alex Rodriguez went 0-for-4 but added an RBI after belting his major league record 24th career grand slam Friday night for a 5-1 win in the series opener.