Sergio Martinez was in a serious struggle through the first half of Saturday’s fight, just like had happened in his most recent fight, in October against Darren Barker. But he ended that fight in style by scoring an 11th-round highlight-reel knockout.  It happened again Saturday night for Martinez, who once again was in a very tough struggle, this time against Matthew Macklin. Macklin had landed several clean right hands and was credited with a seventh-round knockdown when Martinez touched his glove to the canvas.  But Martinez righted the ship. He found another gear, and the thoroughbred pound-for-pound top-three fighter powered his way to another impressive 11th-round knockout to retain the lineal middleweight world championship.  Check it out after the jump. @Shay_Marie x @gametimegirl