Oliver Ekman-Larsson made it 2-0 at 8:32 after Anderson tried to bat away the rebound of Clayton Keller's shot. Garland scored off the rebound of a Brad Richardson shot to increase the lead to 3-0 at 9:40 of the second.
"We knew they were going to come out hard, but we didn't match their compete level early on, and they hemmed us in and they dominated," Tierney said. "And it ended up being too much to come back from."
Carl Soderberg scored the Coyotes' sixth power-play goal in three games for a 4-0 lead at 1:18 of the third.
"We were playing catch-up hockey, which is tough for a team that doesn't score a lot," Ottawa coach D.J. Smith said. "But the second and third period, I really liked our effort. But you don't take anything away from Arizona. They don't give you anything."
Namestnikov scored his third goal in five games with the Senators since being acquired in a trade from the New York Rangers to cut it to 4-1 at 2:58.
"We turned a lot of pucks over early, but as the game went on, I thought we got a lot better," Namestnikov said. "It's hard to play against them because they're very structured and don't give you much. It's always hard to play from behind."
Ottawa was 0-for-22 on the power play until Tierney scored at 4:08 to make it 4-2.
Raanta won for the first time since Nov. 2, 2018, a 4-3 victory in overtime against the Carolina Hurricanes. He missed the final four months of the 2018-19 season with a lower-body injury.
"When you haven't played in 11 months, it doesn't really matter what kind of game it is, you're just happy to be back and playing and enjoying every second," said Raanta, who made 29 saves in his season debut, a 3-2 overtime loss to the Colorado Avalanche on Oct. 12. "We've been playing really good hockey, so when you get a chance to play you want to also contribute and to get the wins."
Lawson Crouse scored into an empty net at 19:05 for the 5-2 final.
