The Rams appeared to be heading for a 2-1 victory at Fratton as the relegation clash entered six minutes of time added-on.
However, Rob Atkinson, who had earlier scored his maiden Pompey goal before putting through into his own net, rode to the rescue by heading home Nicolas Schmid’s long goal kick.
Days earlier the Blues lost in agonising circumstances at Coventry, now they had earned a precious point – and here are Neil Allen’s player ratings...
1. Nicolas Schmid - 8
Stunning late save to push Agyemang’s header over the bar to earn a point. Also nailed Kosznovszky out when the midfielder’s awful pass gifted Derby the ball, but the keeper stood firm to thwart Clark. Such a huge player. Photo: Graham Hunt
2. Terry Devlin - 7
Another eye-catching display from right-back as he continues to flourish. Some strong defending in the second half, especially. Had a great opportunity to extend Pompey’s first-half lead when clean through down the right, but produced a poor pull back. Moments later, Derby levelled. Photo: Graham Hunt
3. Hayden Matthews - 8
A third successive start for the youngster and a display to be applauded against the powerful Agyemang. Strong, good in the air and produced one tremendous late chase back and challenge to deny the striker when clean through. Also lasted the full 90 minutes. A real coming of age performance. Photo: Graham Hunt
4. Regan Poole - 7
Back in the side after a two-game absence with an ankle injury and produced one crucial block to deny Brewster’s goal-bound first-half attempt. As ever, full of fight and heart. Photo: Graham Hunt