Exhibit 32.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of VistaOne, L.P. (the “Fund”) on Form 10-Q for the quarter ended September 30, 2026 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, David A. Breach, Co-Chief Executive Officer of the Fund, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that, to my knowledge:

(1)
The Report fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and
(2)
The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Fund.

 

Date: November 12, 2026

By:

/s/ David A. Breach

David A. Breach, Co-Chief Executive Officer

 

(Co-Principal Executive Officer)

 

This certification is being furnished solely for the purposes of 18 U.S.C. §1350 and is not being filed as part of the Report or as a separate disclosure document.