Ten-man Pompey crashed out of the FA Cup at the first hurdle as they suffered a 1-0 defeat at Luton.
James Collins’ first-half stoppage-time effort proved the difference as Kenny Jackett’s men suffered a fourth straight loss.
The Blues were defensively sound for the majority of the first half but switched off in stoppage-time.
Andrew Shinnie’s cross found Danny Hylton inside the box and the Luton forward teed up strike partner Collins, who steered his first-time effort beyond Luke McGee’s right-hand post.
Pompey attacked with more purpose after the restart and were unlucky not to equalise.
On 59 minutes, Matt Clarke met Matty Kennedy’s corner, but the defender’s header was pushed onto the bar by Luton goalkeeper Marek Stech.
One minute later, Kennedy found Jamal Lowe at the back post, but the winger’s effort was cleared off the line by Alan Sheehan.
However, Pompey’s luck was summed up when Nathan Thompson received a second yellow card when he brought down Collins six minutes from time.
Ben Close forced a brilliant save out of Stech in stoppage-time but it wasn’t to be.
Pompey exited the competition at the first stage for a second successive season, while they’re without a win in their past four games as their troubles in front of goal continue.