Robert Thomas had three assists, and Binnington made 27 saves for the Blues (8-4-3), who have lost three in a row (0-2-1), including 3-2 at the Carolina Hurricanes on Saturday, when Brendan Smith scored the go-ahead goal with 2:57 remaining in the third.
"It's just frustrating," St. Louis defenseman Robert Bortuzzo said. "I think every guy in that room knows how valuable points are, no matter what time of year it is, the League's too competitive, there's too much parity. Strong division. So frustrating to give a few of those away, especially tonight where I thought we had great energy and a little lapse in the second but overall, I thought, good, strong spurts of hockey, similar to [Saturday] night, where we kind of played a good third period. Just frustrating."
On the deciding goal Sunday, the puck was chipped to Draisaitl along the right boards. He cut back and quickly found Yamamoto between Blues defenseman Colton Parayko and forward Vladimir Tarasenko.
"They were back. When Draisaitl turned up, (defenseman Calle) Rosen's on him," St. Louis coach Craig Berube said. "I'd like to see Thomas back off a little bit and be in better position and Parayko out farther on the guy and be tighter. That's basically what it boils down to.
"Yeah, it's disappointing big time. It's disappointing and we've got to be better, and we will be."
Ivan Barbashev scored at 4:06 of the third to make it 4-3, a shot just under the crossbar. Play continued but was eventually whistled by the box signaling a goal.
Tarasenko tied it 4-4 when he tapped in a pass from Pavel Buchnevich at 7:48.