Leyton Orient bowed out of the EFL's Bristol Street Motors Trophy after defeat against 10-man Portsmouth at Brisbane Road.
O's boss Richie Wellens rung the changes from Saturday's FA Cup first-round win over Carlisle, with Academy youngsters Makai Welch and Abdi Mohamud named in the matchday squad for the first time.
And Sam Howes got down well to deny Abu Kamara on six minutes, before Theo Archibald had a tight-angled effort saved at the other end moments later.
Archibald was then clipped on the edge of the area by Sean Raggett, who was given his marching orders as the last man on 19 minutes.
But George Moncur's free-kick was held by Ryan Schofield, before Ruel Sotiriou fired another attempt over from the edge of the box.
A Moncur shot was touched behind on the half-hour mark before O's had a let-off when Christian Saydee missed a great chance from eight yards on 33 minutes.
Jayden Sweeney timed his run to the far post well, but fired just over, before Saydee put Pompey ahead shortly before the interval.
Darren Pratley had penalty claims turned down in stoppage time, with Archibald seeing a curling shot clawed away by Schofield.
Archibald and Ed Turns made way for Ethan Galbraith and Joe Pigott during the break, with Sotiriou denied by a post three minutes into the second half.
And O's were back on level terms before the hour mark as Pigott received the ball with his back to goal and sent a shot on the turn past Schofield for his fourth goal of the campaign.
Jordan Brown blocked a shot from Kamara midway through the second half, before being replaced by Dan Happe in another double change, as Sotiriou made way for Charlie Pegrum.
Tom James saw his cross just evade Pratley and Omar Beckles and drift wide, before Pegrum combined with Pratley and was just off-target.
But Pompey regained the lead on 74 minutes through Kamara, with Schofield producing a stunning save to deny Aaron Drinan an equaliser soon after.
James sent a half-volley just wide six minutes from time, but O's could not get back on terms as they bowed out.
They will now turn their focus back to League One action on Saturday, with Oxford United the latest visitors to Brisbane Road.
Leyton Orient: Howes, James, Sweeney, Turns (Galbraith 46), Brown (Happe 69), Sotiriou (Pegrum 69), Archibald (Pigott 46), Moncur, Drinan, Pratley, Beckles.
Unused subs: Brynn, Welch, Mohamud.
Attendance: 2,371 (including 1,065 Portsmouth fans).
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