Under bright blue, sunny skies at the RusSki Gorki Jumping Center, Stoch had two firsts and a second-place finish in three training runs for Sunday night's individual normal hill final.
Stoch is trying to keep Poland in the forefront of Olympic ski jumping following the retirement of Adam Malysz, who won silver in both the normal and large hills at Vancouver in 2010.
The men who finished around Malysz four years ago also performed well Friday.
Gregor Schlierenzaur of Austria, who won bronze in both the normal and large hills at Vancouver, was second in the third training jump. Olympic gold medalist Simon Amman tied for sixth.
Peter Prevc of Slovenia, second to Stoch in the World Cup standings this season, had three top-six finishes Friday.
Stoch, who has four World Cup wins this season, finished second to Japan's Taku Takeushi by just eight-tenths of a point in the opening training session Friday. He was then was three-tenths of a point ahead of Austria's Thomas Diethart in the second.
Stoch dominated the third run, finishing with 76.1 points to Schlierenzauer's 72.9.
In his first three runs Thursday, he finished 10th, 20th and 22nd. The improvement Friday prompted him to give the hill a nickname.
"I called her a mean girl," Stoch said. "She is not my best friend yet, but is becoming a good colleague."
The 32-year-old Amman, competing in what he says will be his last Winter Games, is bidding to win a record fifth Olympic gold. He had a busy day planned for Friday, when he was also serving as flagbearer for Switzerland at the opening ceremonies later in the day.
"I've been asked twice to do it but it was difficult to do, walking around for hours, not losing too much energy," Amman said. "This is my fifth Olympic Games and I'm looking for something extra. It will be nice."
Thomas Morgenstern of Austria, who returned to jumping in Thursday night's opening training runs after a nasty accident in practice in early January, didn't practice Friday. Also taking a break were Japanese veteran Noriaki Kasai and Anders Jacobsen of Norway, who crashed while landing on his first jump Thursday.
Absent as well Friday were the big crowds, with only a few dozen spectators sitting in the metal stands at the finishing area in the stadium.
The men return to the normal hill Saturday evening for qualifying, with the top 10-ranked World Cup jumpers guaranteed a spot in the 50-man Sunday final. There will be two rounds in the final, with 30 advancing for a chance for medals in the second round.
Women ski jumpers make their first appearance on the normal hill Saturday, followed by another training session Sunday before their historic first Olympic final Tuesday.