Smith and Lou Williams were sent back to the team hotel earlier in the day because they were feeling ill, but both opted to play. Williams finished with 11 points off the bench.
Smith hit four of his first five shots as the Hawks jumped out to a 22-9 lead.
Portland whittled the advantage down to 28-24, but Atlanta built up another large lead when the Blazers subbed in the likes of Sasha Pavlovic, Will Barton and Ronnie Price. Devin Harris scored to put Atlanta back up 41-26 halfway through the second quarter. After the Blazers' first team came back in, they cut into the advantage again and trailed 56-47 at halftime.
Batum led a small comeback, scoring 11 points in the third quarter as Portland got within 68-63, but the Hawks kept the lead until deep into the final period.
"We keep putting ourselves in holes," Matthews said. "We can't keep doing that to ourselves."
NOTES: Bailey Leonard, brother of Portland rookie Meyers Leonard and a war veteran, was honored before the game along with other military veterans. ... Atlanta C Johan Petro sat out for the sixth straight game with a lower back injury. ... The Hawks round out their trip with Golden State on Wednesday and Sacramento on Saturday.