Germany got off to a flying start at the 2006 Winter Games, taking gold in the opening two events.
Biathlete Greis claimed the first gold medal in Turin
Michael Greis upset Norway's defending champion, Ole Einar Bjoerndalen, in the men's 20km biathlon while Georg Hettich added a second in the nordic combined.
American speed skater Chad Hedrick began his bid for a five-gold sweep with victory in the men's 5,000m.
British biathlete Tom Clemens finished 57th, while Adam Rosen led Britain's luge hopes with 18th after two runs.
Canadian Jennifer Heil claimed the only other gold medal up for grabs on day one with her victory in the women's moguls freestyle skiing.
Earlier, the German team suffered a blow when Olympic champion Evi Sachenbacher lost her appeal against a five-day ban for excessive levels of haemoglobin, while four more cross-country skiers were also suspended.
DAY ONE EVENTS
In the women's moguls, favourite Jennifer Heil gave a near flawless display to clinch gold.
World Cup leader Heil, who eased through qualification earlier with the best score, earned 26.5 points, enough to beat defending Olympic champion Kari Traa of Norway by 0.85.
Surprise package Sandra Laoura of France took bronze while world champion Hannah Kearney failed to make it past the heats.
In speed skating, Chad Hedrick claimed the first American gold medal of the Games with victory in the men's 5,000m.
The two-time world champion, who is aiming for a record-equalling five-gold sweep in Turin, clocked a winning time of six minutes, 14.68 seconds.
Hedrick will also skate the 1,000m, 1,500m, 10,000m and new team pursuit event.
Sven Kramer came second while Italy's Enrico Fabris edged another Dutchman, Carl Verheijen, by 0.59 seconds to capture bronze - the hosts' first medal at this year's Olympics.
In figure skating, twice world champions Tatiana Totmianina and Maxim Marinin got their Olympic pairs title bid off to the perfect start with a dazzling short programme.
The Russian duo nailed each of their eight specified elements to outclass Chinese rivals Zhang Dan and Zhang Hao with a score of 68.64 under the new judging system which is making its Games debut.
They established a 3.92 points advantage ahead of Monday's free-skate.
Michael Greis won the first gold of the Games in the men's 20km biathlon.
He finished 16 seconds ahead of second-placed Ole Einar Bjoerndalen.
Norwegian Bjorndalen, who won four events in 2002, was set to enter five competitions this time around in an effort to become the most successful Winter Olympian in history.
His team-mate Halvard Hanevold took bronze.
There was another shock German victory in the men's individual nordic combined Gundersen.
Georg Hettich triumphed, with Austrian Felix Gottwald claiming silver and Norway's Magnus Moan third.
Two of the event's favourites, Finland's Hannu Manninen (ninth) and Ronny Ackermann of Germany (18th), disappointed.
The men's luge competition got under way with local favourite Armin Zoeggeler in charge after the opening two runs.
The 32-year-old defending champion clocked a combined time of one minute, 43.132 seconds.
He was 0.158 seconds ahead of Russian Albert Demtschenko going into Sunday's two final runs, with triple Olympic champion Georg Hackl, 39, back in fifth.
US-born Adam Rosen led Britain's hopes, in 18th place, while Mark Hatton finished the second of four runs in 25th.
Veteran Japanese ski jumper Masahiko Harada was disqualified from the normal hill competition for having skis that were too long for his weight.
The two-time world champion, who was a member of Japan's gold medal-winning team at the 1998 Nagano Games, would have been the oldest competitor in the event.
He could still take part in the large hill and team events.
Team-mate Noriaki Kasai did make it through qualifying with the longest jump of the evening, 103 metres
Women's preliminary rounds kicked off the ice hockey programme with Finland beating Germany 3-0, and Sweden overcoming Russia 3-1
The other matches saw USA triumph 6-0 against Switzerland, while Canada thumped Italy 16-0.