Raiders defensive end Khalil Mack had a critical sack of Geno Smith on Sunday, a play that also caused a fumble and likely kept the Giants from scoring just before halftime in Oakland’s 24-17 win at the Coliseum. But the more satisfying sack and forced fumble in the Raiders’ 24-17 win may have belonged to linebacker Bruce Irvin, who was a teammate of Smith in college at West Virginia. “I went two years and couldn’t hit Geno in practice,” Irvin said. “It felt good.” Irvin’s strip-sack was also key, coming at Oakland’s 36-yard line and leading to a 12-play, 47-yard drive and 39-yard field goal by Giorgio Tavecchio. Irvin rushed untouched off the right edge, knocking the ball from Smith’s hand. Irvin said that as he neared Smith, his eyes got “big, bro.” “It was a big moment,” Irvin said. “We pride ourselves on turnovers. We haven’t been getting a lot this year, but they’re starting to come.” Denico Autry added a fourth-quarter sack, and the Raiders have eight sacks in their past two games after totaling 14 sacks in their first 10.