Italy's Alberto Tomba won his second consecutive World Cup ski race in three days yesterday with a victory in the giant slalom in Sestrieres, Italy, that prevented Sweden's Ingemar Stenmark from a record 86th triumph.

Tomba, 20, already dubbed the successor to Gustav Thoeni, the Italian four-time World Cup champion, won the special slalom Friday.

Tomba was third-fastest in the first run and second-fastest in the second down the Kandahar track to clock a winning aggregate of 2 minutes 19.51 seconds.

Stenmark, the World Cup races leader with 85 wins in a 14-year career, was the runner-up, nine-hundredths of a second back.

Tomba has 50 points in the overall Cup standings, well ahead of Swedes Jonas Nilsson (21 points) and Stenmark (20).

Felix McGrath, from Princeton, N.J., was the only U.S. finisher. He came in 29th . . .

In Kushiro, Japan, the Soviet world champion pair of Natalia Bestemianova and Andrei Bukin easily won the ice dancing as the three-day international free skating competition for the NHK Trophy ended.

Another Soviet pair, Svetlana Liapina and Georgy Sur, came in second with 2.4. The American pair of Susan Wynne and Joseph Druar finished third with 4.2.