George Saville scored his first goal back at Millwall as the Championship side came from behind to defeat Portsmouth 2-1 and reach the second round of the Carabao Cup.
Saville returned to the Lions from Middlesbrough during the summer and his smartly-taken volley eventually saw off League One Pompey, who had defender Callum Johnson sent off.
Reeco Hackett-Fairchild gave Portsmouth the perfect start when he seized upon a sloppy pass before running into space and slamming a shot into the bottom corner in just the fourth minute.
Millwall recovered from that early blow to level after 20 minutes when Jed Wallace's shot was pushed out by Pompey goalkeeper Alex Bass into the path of Scott Malone, who tucked away the rebound.
The turnaround was complete before the half-hour, as Saville did well to steer a volley from Wallace's cross into the corner from around the penalty spot.
Pompey's task was made much harder three minutes after the restart when Johnson was shown a straight red card for his challenge on Tom Bradshaw.
Matt Smith almost added a third for Millwall when his header struck a post, while Hackett-Fairchild almost forced penalties late on when his effort was nodded off the line by Ryan Leonard.