Coach McLellan added he hasn't been surprised with Rattie's play.
"We've got to remember, Ty's a pretty offensively creative player. He's scored a lot in his career, especially through his junior days. Maybe it hasn't happened for him as much at the NHL level but the opportunity he's getting now to play in the top six or top three and the amount of icetime, he's taking advantage of it.
"I don't know if he's ever got that chance. He's getting it now and we'll see if he can sustain it. He's fit that line well. He thinks the game at their level and puts himself in a good spot."
Oilers had a strong opening period, taking the play to the Senators for the majority of the first 20 minutes.
Early on, Nugent-Hopkins fed McDavid at the top of the crease but Senators starting goaltender Craig Anderson made a nice save, turning the Oilers captain away on the backhand attempt.
8:23 into the game, Oilers scored first. After a point shot from Darnell Nurse that was tipped by Pontus Aberg, Caggiula picked up a loose puck in the crease and backhanded it into the wide-open net for the goal.
5:10 into the second period, Nugent-Hopkins made a great pass off the left side boards to McDavid in front. McDavid made no mistake, rifling it past Anderson to double the Oilers lead to 2-0.
McLellan talked about the team getting its third win on a single road trip for the first time all season.
"Three was a big number for us. We got to two and before the game tonight we talked about three. We hadn't got there on any of our road trips (this season). Not every one's a four-game or five-game but when we had the opportunity, we'd fall short so we considered this a successful one and we want to go home and continue to move the needle forward.
"What caused it? Everybody's contributing. We're scoring a little more, the penalty kill's improved, the power play found a way to score one finally tonight. A lot of areas of the game that are going the right way right now."