The 17-year-old won the season opener in Cardrona in August and, after opting out of the next leg in Copper Mountain, returned to finish second at round three in Park City.
And Yater-Wallace was back to winning ways at the penultimate World Cup round of the season in Sochi, the leg also acting as the test event for next year's Olympics in the same venue.
He produced a best score of 93.8 from his second run with American teammate Gus Kenworthy taking second with 90.0 and Mike Riddle third with 88.2 in Russia.
Another American David Wise was fifth with Yater-Wallace now leading the overall halfpipe World Cup standings by 75 points with only 100 more on offer at the final round.
That will come in Sierra Nevada at the end of March with the Freestyle World Ski Championships in Voss at the start of next month next on everyone's agenda.
Switzerland's Virginie Faivre will head into the worlds in high spirits after winning the women's event in Sochi, her first of the season which puts her into the overall lead.
The margin of victory was tight though as she scored 80.8 from her first run to just pip Rosalind Groenewoud of Canada who produced an effort of 79.0 with her opening outing.
Canadian teammate Keltie Hansen completed the top three with a first run score of 76.4 with Faivre leading the overall halfpipe World Cup standings by just eight points.
Winter X Games superpipe champion Maddie Bowman, winner of the last two events, was 11th to surrender the lead while Ayana Onozuka, who was seventh, is only eight points behind her in third.