The Late Late Show Sees off Saints
After his assist Cavani soon gave the away side parity with a stooping header.
The number seven then completed the comeback in the second of five minutes of added time. The goal arrived in all to simple a fashion.
A freekick was laid off to Marcus Rashford who places it with pace into the box. The half-time substitute connects his head with the ball which diverts it past a helpless McCarthy.
The striker timed his movement well and found plenty of space between three Southampton defenders. By the time the ball was in flight it was already too late for the backline.
A bitter end to a promising afternoon.