Bottom-Two-Runoff IRV (BTR-IRV) is a voting system that selects a single winner using votes that express ranked preferences. BTR-IRV passes the Condorcet Criterion, and is by definition a Condorcet method.
BTR-IRV was conceived as a sort of Instant-runoff voting-Condorcet hybrid, in that the runoff it uses is very similar to IRV, but the runoff doesn't ever eliminate a Condorcet Winner.
The process is as follows: take the two options with the fewest first preference votes. The pairwise loser out of those two options is eliminated, and the next preferences from those ballots are redistributed. This process repeats until there is only one option remaining, and that remaining option is the winner.