A sequence of two coronal mass ejections (CMEs) impacted Earth in early September 2025, producing consecutive geomagnetic disturbances. The first CME, launched on 31 August 2025 and observed as a halo in SOHO/LASCO imagery, reached Earth on 1 September (~20:45 UTC), generating a clear interplanetary shock. OMNI 1-min solar-wind data show a sudden rise in |B| from ≈ 5 nT to > 25 nT, proton density and velocity increases (≈ 350 → 600 km s⁻¹), and a southward IMF Bz interval that drove enhanced coupling. The Kyoto Dst index recorded a sudden storm commencement followed by a minimum of −75 nT on 2 September, confirming a moderate geomagnetic storm. A second CME erupted from the Sun on 3 September 2025 and was detected at L1 around 5 September, marked by another |B| and V enhancement (up to 15–18 nT and > 500 km s⁻¹). This later impact produced a weaker geomagnetic response, demonstrating multi-CME interaction within one week. MMS observations show magnetospheric compression, enhanced ion temperature, and fast Vx flows coincident with the first event, illustrating how successive CMEs influence the solar-wind–magnetosphere system.