“This is the most emotional moment of my career. Last season was incredibly exhausting and incredibly hurtful,” he said, adding the result gave him “satisfaction.”
“I thought my run might be good enough for fifth place and I would have been super happy with that,” said Feller, who has five career podium results but is yet to win a race.
Schwarz completed the strong showing of the Austrian team, trailing Feller by four hundredths in third.
Austria is still chasing a first win in a slalom or GS since record eight-time overall champion Marcel Hirscher retired in 2019.
Vinatzer lost his first-run lead as he posted the 23rd time in the final run, missing the podium by seven hundredths in fourth.
The Italian had surgery in November and missed a parallel World Cup event in Austria.
He attempted a comeback to racing in a slalom on the lower-ranked European Cup circuit last week but failed to finish his opening run of the event in Val di Passa, before skipping a second race at the same resort the following day.
But Vinatzer looked back to his best upon his return to the World Cup on Monday.