Vorobiev, who entered the game with one goal and three assists in 19 NHL contests, was a last-minute substitute on the line for Eric Daze.
Daze tweaked his back in the pregame warm up, Blackhawks coach Trent Yawney said. Daze had surgery to repair herniated discs in his back three times in five years.
Yawney coached Vorobiev for two years at Norfolk of the AHL and wasn't surprised by the winger's performance.
"He's a world-class player and makes world-class plays and showed that again," said Yawney, who earned his first NHL coaching victory. "He's just starting to evolve.
"It's just the tip of the iceberg. I've seen him play some games in the minors when he was just totally dominating."
Vorobiev, 23, said just shooting more -- something Yawney has stressed to him -- paid off against San Jose.
"Now I feel more comfortable and have more confidence," Vorobiev said. "It doesn't matter where I play. I'm going to play my game, my way.
"I try to shoot the puck more now and it's OK."
Jim Vandermeer, Tuomo Ruutu, Tyler Arnason and Jassen Cullimore also scored and defenseman Brent Seabrook had four assists as Chicago clicked for three power-play goals -- including two 5-on-3 conversions -- in seven chances.
Seabrook tied the Blackhawks records for assists and points in a game by a rookie.
"The guys were sharp on the power play," Seabrook said. "In the new NHL, that's the way you've got to be, you've got to bury your chances. I just distributed the puck, and the guys did the rest."
Nikolai Khabibulin stopped 21 shots to earn his first victory with Chicago. Khabibulin, who backstopped Tampa Bay to the Stanley Cup title in 2004, signed a four-year, $27 million deal with the Blackhawks in August.
"It's always good to get the first one for everybody's confidence," said Khabibulin, who gave up five goals on 24 shots in a loss to Anaheim on Wednesday. "The last game wasn't good for us. Tonight we got a good break with the power plays early on."
"It wasn't exactly the start we wanted," coach Ron Wilson said. "The first shot went in, we misread an assignment and then we got ourselves in penalty trouble."
"Partly he (Toskala) wasn't seeing it, but partly he was a victim of circumstance," Wilson said. "The first goal he was screened and the last goal he was screened. The other two were 5-on-3s, it was kind of a mercy pull."
The Sharks went 2-for-8 on the power play.
The Blackhawks led 3-0 at 7:21 of the first period.
Vandermeer opened the scoring just 29 seconds in with a 40-foot shot that sailed just beyond Toskala's outstretched glove.
A pair of 5-on-3 goals, scored by Ruutu and Arnason 90 seconds apart, made it 3-0.
After a quick fake, Ruutu ripped a shot from the slot over Toskala's glove at 5:51 to make it 2-0. Arnason then fired Vorobiev's pass from across the slot in off the inside of Toskala's right pad at 7:21.
Cullimore extended the lead to 4-0 at 1:49 of the second with a power-play goal from the left point.
Following the goal -- and with Chicago holding a 14-2 shots advantage -- Nabokov replaced Toskala.
Sturm pounced on a rebound of Scott Hannan's shot for a power-play goal at 5:14 to cut it to 4-1.
Vorobiev replied at 8:45 to make it 5-1. His second goal at 1:33 of the third came when he beat Nabokov on the short side from the top of the right circle.
McLaren fired in a loose rebound at 2:01 to make it 6-2. Michalek completed the scoring with a power-play goal with 2:34 left.
- Chicago D Adrian Aucoin played only four minutes because of a groin injury. He is day to day.
- Blackhawks D Jaroslav Spacek missed his second game with sore ribs.
- San Jose D Josh Gorges, 21, played in his first NHL game.
- The game drew an announced crowd of 11,823. The Blackhawks' opener on Wednesday drew 16,533.