It was an important match in the context of playoff seedings, with the Thunder facing a tougher run home.
In their final seven matches, the Oklahoma City side will only meet one team eliminated from playoff contention, with dates against five of the top nine teams in the West.
Portland meet a similar run home, with two games in hand on OKC. Of their nine remaining games, they'll face teams out of playoff contention three times, as well as two teams on the fringe of a playoff spot in the West.
Both needed the result in Monday's match, and Portland got it.
Given how the game started, the Thunder did well to get back into the match. Portland started the match by scoring the first seven points, and found themselves ahead 19-6 inside the first five minutes. Inside those opening exchanges, Adams was the only Thunder player to score.
The visitors continued to dominate the period and led 34-17 after the opening quarter.
The Thunder made a strong comeback in the second quarter and clawed back to within five points at half time, thanks to a strong contribution from the bench.
The game was in the balance from there and both sides held the lead at times. In the end, it was the cool head of Portland shooting guard CJ McCollum the made the difference, with his 34 points leading the visitors to a season sweep over the Thunder.