High-strength aluminium alloys attract continuous research interest, owing to their wide use in aerospace and terrestrial transportation industries. The performance of the alloys is essentially determined by nanoscale precipitates, thus understanding the structure and formation mechanism of the precipitates during thermal processing is of great importance. Here, we reveal complementary domain structures in precipitates in a high-strength Al-Zn-Mg-Cu alloy using a combination of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Through the transfer of fivefold symmetry polyhedra at domain boundaries, the intermediate precipitates develop two sets of highly ordered and structurally complementary nanoscale domains in their nucleation and growth. This new type of atom packing maintains the topologically close-packed structure inside the precipitates while reducing the lattice misfit with the Al matrix and the barrier of structural transformations on two interfaces, demonstrating good thermal stability. Our discoveries lead to insight into the precipitate evolution in the Al-Zn-Mg-Cu alloy system and can help understand other precipitation processes of complex structured phases. Furthermore, the evolution process demonstrates an advanced mode of building metastable architectures with nanoscale interlocking pieces in alloy matrixes, which may inspire strategies to obtain high-strength, lightweight and thermostable alloys.