Jason Banton's superb solo effort on the counter had put the visitors in front midway through the first half but the Dons responded immediately as Pell found space to bundle home.
After the break it was the hosts who looked the more likely winners, Pell and Sammy Moore both going close as Argyle held out valiantly.
Banton gave the visitors the lead In the 26th minute as Pell was caught in possession, allowing Reuben Reid to release the youngster who finished clinically on his left side for his third goal of the season.
But just two minutes later the Dons were level, Pell making up for his mistake by volleying home his first goal for the club after Argyle failed to clear their lines.
Ronan Murray missed a golden chance to put Argyle back in front before the break but it was Neal Ardley's side who dominated after the interval.
Substitute Jessie Darko fired narrowly over while Moore's volley forced a fine save from Jake Cole but Argyle held on in the end for what could prove to be a vital point.