Grant scored off a Blues turnover behind their net to make it 2-0 at 5:41. Pietrangelo tried to backhand a pass to Ivan Barbashev, but it caromed off Nicolas Deslauriers' skate to Grant in front.
"It's always nice to score," Grant said. "When we get ready for games, our line, our first mindset is to be hard to play against, [and] second, be good in the D-zone. We start a lot of times in our D-zone and that's the most important thing for us. Obviously you want to be able to go play and use your offensive abilities and contribute, especially when we've been struggling to score goals as a team, so it's always nice to get that."
Dunn scored at 3:14 of the second period to cut the Ducks lead to 2-1, but Grant's second of the game came on a shorthanded breakaway after a Justin Faulk giveaway at 7:20 to make it 3-1.
"It was only two mistakes for me defensively," Blues coach Craig Berube said. "... We use (the drop pass) a lot. It works pretty well. It was just a mistake."
Grant completed the hat trick, scoring into an empty net at 18:21 of the third period for the 4-1 final.
"Derek's effect on the scoreboard is usually by keeping it out of our net," Ducks coach Dallas Eakins said. "For him to put three in their net is obviously huge for our group. We'll take the scoring from wherever we can right now."
