Lucas Barbosa and Rudson Mateus met 6 times on record, and Barbosa holds a 5 to 1 edge. All 6 meetings landed in a tight window across 2018 and 2019, both men fighting at medium-heavy. Only one of those matches ended by submission: Barbosa's Arm Triangle Choke at BJJ Stars 2 in 2019. The rest were decided on the scoreboard, with two wins by points, one by advantage, one by decision, and Mateus taking his single win by decision in the round robin at the 2019 King of Mats Abu Dhabi.

The records point to two different builds. Barbosa carries 214 recorded matches with a 79% win rate and finishes 38% of his wins by submission. Mateus has 77 recorded matches at a 73% win rate but a higher finishing rate, submitting in 52% of his wins, with the armbar his most frequent finish at 18 wins. In their shared matches, though, Barbosa's edge came less from finishing and more from grinding out decisions and margins.

Most of their meetings were high-level bracket work rather than one-offs. They crossed in the semi-finals of the 2018 World IBJJF Jiu-Jitsu Championship, in a 2018 Brazilian National round of 16, and in the final of the 2019 Abu Dhabi Grand Slam. Barbosa won all three of those.