Serena Williams overpowered Victoria Azarenka 6-1, 6-3 Sunday, winning the Madrid Open and leaving her top-ranked opponent so exasperated she smashed her racket to the ground. In a match between two of the tour's heaviest hitters, Williams battered Azarenka on the new blue clay court with big serves and fierce returns. The 13-time Grand Slam winner captured the first four games and had no trouble the rest of the way. ''I can still do better,'' said Williams, who took a yearlong absence because of illness in 2011. ''This is really good. I have been working hard. I had some tough battles and really unfortunate circumstances so I really love this…