Over on the snowboard halfpipe, Australia's Torah Bright sliced her way to her country's first gold of the Vancouver Games and speedskater Christine Nesbitt picked up the third gold for host nation Canada.
Norwegian biathlete Tora Berger made an Olympic milestone for her country when she skied and shot her way to the country's 100th Winter Games gold, the first nation to achieve that mark.
Emil Hegle Svendsen, her team mate, quickly made that 101 in the men's biathlon 20km individual.
Gliding to victory
Lysacek's win - the first American figure skating gold since Brian Boitano's in 1988, also in Canadian hosted Games in Calgary - consolidates the US position on top of the medals table with six golds.
Unlike Plushenko, who had been strongly favoured to win, the American did not have to attempt any quadruple jumps to win over the judges.
"I couldn't have asked for much more than that," Lysacek said. "To get a personal best in the most important moment of my life - you dream about it."
Meanwhile, Riesch put her gold in the women's super combined crown down to getting her nerves under control.
All eyes had been on her rival downhill darling Vonn but she clipped a gate and tumbled within sight of the finish line.
"I put it all out there and it just didn't work out for me," Vonn said.
Canada's 'curse' broken
Riesch's win moves Germany to second in the medal standings on four golds, with Norway, South Korea, Switzerland and Canada on three each.
Canada's "own the podium" programme for the home Olympics has begun to reap respectable rewards with Nesbitt's third gold for the home crowd.
|Maria Riesch gold moves Germany to second
place in the medal standings [AFP]
She claimed the Olympic title by two-hundredths of a second, saying afterwards that the way she raced "wasn't pretty".
"I was fortunate to win Olympic gold. It was probably the worst 1,000 I've done this year," she said.
The Canadian gold rush comes after the country broke on Sunday its so-called "curse" of never having won Olympic gold on home soil, previously in Montreal in 1976 and Calgary in 1988.
Hosts Canada could also claim Thursday as a good day for the Winter Games overall, with no new reports of operational snags.
The beleaguered organisers have seen a string of problems, ranging from million-dollar ticketholder refunds to unreliable ice grooming machines.