The Serie A giant was set to head through as runner-up, but Francesco Pio Esposito and Alessandro Bastoni netted important goals in the second half.

There was little quality on show in the first half as the teams had a combined one shot on target, but Inter improved after the break, with Lautaro Martinez poking a shot against the right post 51 minutes in, before Franco Armani denied him with a smothering save just moments later.

Lucas Martinez Quarta was then shown a straight red card in the 66th minute after sliding in as the last man on the back of Henrikh Mkhitaryan, which opened some much-needed space for Inter.

Petar Sucic slid a lovely through-ball into Esposito in the box, and the 19 year-old coolly stepped away from his marker to guide his first Inter goal into the bottom-right corner.

Mkhitaryan then blazed a shot over while one-on-one with Armani before Bastoni skipped over two sliding challenges to fire the goal that sealed all three points under the goalkeeper in stoppage time.

Gonzalo Montiel received a second yellow card in the 95th minute for dissent, marking a disappointing end to the Club World Cup for River.

Inter goes through as group winner on seven points, having enjoyed an unbeaten group stage, and will face Fluminense in the last 16.

Meanwhile, Monterrey qualified as group runner-up; having drawn its first two matches, the Mexican side recorded a 4-0 win over Urawa Reds in the final game to leapfrog River into second.