World No. 174 Lucas Pouille clinched by far his biggest win of the season on Monday when he stunned world No. 26 Karen Khachanov in his Madrid opener. Pouille, who was awarded a wildcard into Madrid, handed a 6-3 6-4 loss to Khachanov in the Madrid first round. Pouille, a former world No. 10, is now ranked outside the top-150 and far from the game that once was making him one of the best players on the ATP Tour. On Monday, Pouille reminded a bit of the player he once was as he delivered a good perfo …