On 12 August 2018, Thiago played the first competitive match of the season under the new club manager Niko Kovač and also scored a goal in a 5–0 victory over Eintracht Frankfurt as Bayern won the 2018 DFL-Supercup. On 18 May 2019, Thiago won his sixth consecutive Bundesliga title as Bayern finished two points above Dortmund with 78 points. A week later, Thiago won his third DFB-Pokal as Bayern defeated RB Leipzig 3–0 in the 2019 DFB-Pokal Final.