Yielding home runs in bunches and making mental and physical mistakes in bunches are the marks of a mediocre team, not a defending world champion. In the past five games, the Giants have been the epitome of mediocrity. "It's always frustrating when you lose," Buster Posey said. "I don't sense any tension or anybody overly frustrated. It's more of a drive and willingness to want to work and get back on track." It'll have to wait another day. On Sunday, the Giants extended their season-high losing streak to five games, falling 6-4 to the Padres. It's their longest skid since a five-gamer, July 25-30, a streak that began against the Padres with a game that Jason Marquis won and Huston Street saved. Just like Sunday's. Marquis out-pitched Ryan Vogelsong, who surrendered three home runs - a theme for Giants starters - and Street overcame Pablo Sandoval's fourth single and retired Posey to complete the Padres' first sweep of the Giants since 2010. "When you're in a streak like this," manager Bruce Bochy said, "it's a number of things, whether it's pitching, hitting with runners in scoring position or defensively. That's what's happening with us."