Manchester City took their January spending to £180million after striking a deal worth £50.2m for Porto midfielder Nico Gonzalez.
The Premier League champions have spent more in this window than all other previous winter transfer markets combined under Pep Guardiola as they strive to get their season back on track.
Gonzalez, 23, underwent his medical in Portugal ahead of signing a five and a half year contract. Barcelona also received a 40 per cent sell-on as part of the deal.
A club statement read: 'Manchester City is delighted to confirm the signing of Nico Gonzalez.