Toffoli, a 21-year-old center who was taken in the second round of the 2010 draft, has six goals - four have been game-winners - and 11 points in 14 games since he was recalled from the minors on Nov. 2. His only other two-goal game in the NHL was on Nov. 9 at Staples Center in a 5-1 win over Vancouver.
Toffoli made his NHL debut late last season and opened some eyes with his stellar play during the playoffs with two goals, four assists and a plus-5 rating in 12 games.
''It definitely helped, getting that experience last year, especially in the playoffs,'' Toffoli said. ''It's not easy stepping into the playoffs - and being able to get the opportunity to do that, I definitely learned a lot.''
Scrivens, who has performed brilliantly in place of the injured Jonathan Quick, was heading toward his fourth shutout of the season when Kevin Shattenkirk and Vladimir Tarasenko scored in the final 5:54. Shattenkirk's goal came 6 seconds after the Kings killed off a power play caused by Colin Fraser's slashing penalty.
''We showed character in the third by pushing back a little bit,'' Blues captain David Backes said. ''But at some point, we need to learn our lesson that if you give good teams leads, it's a heck of an uphill climb to try to get back in the game.''
Scrivens has given up fewer than three goals in each of his last 10 starts and has posted two shutouts since Quick went on injured reserve with a groin strain on Nov. 12 at Buffalo.
''I feel pretty good. I don't feel fatigued right now,'' he said. ''I know when Quickie will be back, or when he's scheduled to be back, so I've got to make sure I get my time when I can.''
Los Angeles has allowed fewer than three goals in a franchise-record 13 consecutive games. The streak includes a pair of 3-2 shootout losses to Buffalo and San Jose.
''They force you. They're a physical, hard-checking team. But we have to have a better reaction than we did,'' coach Ken Hitchcock said. ''They took it to us. We revved it up halfway through the hockey game, but you can't play like that.''
Jaroslav Halak made 20 saves for the Blues, who have lost consecutive games in regulation for the first time this season following their 6-3 defeat at San Jose on Friday. Halak had allowed just five goals in his previous five starts after getting pulled with a 3-0 deficit in the first period of a 4-1 loss at Washington on Nov. 17.
The Kings, who hadn't had a first-period goal in any of their previous four home games - all losses - opened the scoring at the 10:38 mark. Stoll got the puck from Justin Williams near the top of the left circle and took a 40-foot wrist shot that glanced off defenseman Barret Jackman's leg and past Halak with Dustin Brown screening the goalie.
Toffoli made it 2-0 at 16:13 of the period, beating Halak from short range after Drew Doughty's long snap shot from the high slot deflected off Toffoli's stick and Halak's right shoulder before hitting the crossbar. He gave the Kings a three-goal cushion at 5:48 of the second, scoring from the low slot after Willie Mitchell's wrist shot from the left point caromed off teammate Mike Richards.
''We tried to approach this one with maybe a little bit more focus and attention to detail,'' Scrivens said. ''We obviously know they've got an extremely potent power play, so you can only give them so many chances because they're going to find a way to bury one.''
NOTES: St. Louis has yet to be shut out this season. ... The Kings eliminated the Blues from the playoffs in each of the previous two seasons. In 2012, they beat St. Louis in the second round on the way to their first Stanley Cup title. The Blues, who entered the NHL with the Kings in the 1967 expansion, are still looking for their first Cup. ... Brown has been held to a goal and an assist in his last 13 games. ... The Kings are 8-0-0 when leading after two periods, and haven't allowed a first-period goal in their last seven games at Staples Center. ... Los Angeles is 0 for 20 on the power play over its last six games.