For the second successive week, Eddie Jones's tourists prevailed in a see-saw try-fest, crossing the line four times through Charlie Ewels, Piers Francis, Danny Care and Will Collier.
The cool playmaking and kicking of flyhalf George Ford, who compiled 15 points capped by his decisive 74th-minute drop goal, was also instrumental as the match lay in the balance going into the last quarter.
Argentina, who lost a remarkable first test 38-34 in San Juan, again had their moments at the Estadio Brigadier General Estanislao Lopez, holding the initiative midway through the first half and scoring three tries themselves through Joaquin Tuculet, Pablo Matera and Emiliano Boffelli.
Yet after Ford's drop goal at last gave the Six Nations champions breathing space, England repelled the Pumas' final push as they sought in vain to become only the second team to beat Jones's side in his 20-match reign.
"I think we found a way to score points. Today wasn't a great performance but we maximised any errors Argentina made," Jones said afterwards.
"It's always good to win, especially against a tough opponent like Argentina. They should be congratulated for the rugby they play."
The match proved as open, fast and as the first Test had been with the result still impossible to call after Boffelli's converted try on the hour made it 25-25.
Yet a driven line-out, finished by replacement Collier, edged England ahead for the fifth and last time in the match, before Ford's drop goal.
England's youngsters -- they blooded 11 new caps on this tour -- then held firm to clinch only England's second series win in Argentina.
Yet experience won the day too with Ford and Care both excellent at controlling affairs behind the scrum and fullback Mike Brown producing two pieces of counter-attacking brilliance to set up the tries for Francis and Care.
(Reporting by Ian Chadband, editing by Ed Osmond)
