Ammann jumped 128 and 131 meters for 284.4 points in the large hill event. He extended his overall World Cup lead to Austria's Gregor Schlierenzauer to 107 points with three events left.
Polish veteran Adam Malysz - who took two silvers behind Ammann at the Olympics - was second Sunday with 274.3 points (126-130 meters). Austria's Thomas Morgenstern was third with 272.4 points (123.5-130), leaving Schlierenzauer in fourth with 264.9 points from 124 and 127 meters.
The 28-year-old Ammann became the first ski jumper to win four individual Olympic golds after sweeping both individual events in Vancouver. Now he's in good position to win the overall World Cup for the first time, while also eyeing a first medal at the ski flying world championships later this month.
“The main goal is to win the overall,” Ammann said.
“Winning here in Lahti for the first time was a good sign for the work with recovering from the Olympics, it is not easy to do it in time.”
