Mastercard made a £233m bid to take over payments firm Earthport today, scuppering rival Visa attempts to buy the British company.
Mastercard's offer is at a 10% premium to Visa's £198m offer.
Earthport's shares, which have jumped four-fold since the offer period began, added another 25% in light trading today.
The US company said the Earthport deal would allow it to expand its cross-border network service, the same reason cited by Visa when its made its bid in December.
Payment processing has become one of the hottest areas for dealmaking in the last two years, driven by technological changes in the way consumers pay for products.
Earthport offers a lower-cost alternative to traditional payments systems by allowing banks and money transfer firms to have a single relationship instead of multiple ties with various payments channels around the world.
Earthport's directors have unanimously recommended Mastercard's offer and withdrawn their recommendation for Visa's proposal, the company said.
The company's shares, listed on the London Stock Exchange's secondary market, fell more than 28% in 2018 amid growing losses and expenses.
This forced the firm to say in November that "fundamental" changes were required in its strategy.