On Sunday, England will look to end a winless run against France that dates back to 1974.
This victory over Portugal in Tilburg ensured the good work in the matches against Scotland and Spain did not go to waste as England sealed top spot in Group D.
Although it was far from a persuasive England performance, the fringe players brought in by manager Mark Sampson earned the three points.
Duggan chipped in to punish a goalkeeping blunder, and Parris fired home in the 48th minute to restore England’s lead after Portugal had become the first team to score against the Lionesses at this tournament.
It made Sampson’s team the first senior England side, male or female, to take maximum points in the group stage of a European Championship finals.
But watching France coach Olivier Echouafni would have learned little ahead of Sunday’s match, which will be played in Deventer.
Sampson made 10 changes, with only Millie Bright surviving from the starting line-ups that impressively saw off Scotland and Spain.
Laura Bassett, the defender whose own goal against Japan in the 2015 World Cup semi-finals ended their title hopes in that tournament, captained the side.
In came three players each with over 100 caps, in right-back Alex Scott and midfielders Fara Williams and Karen Carney, while Duggan reached a half-century of England appearances.
Duggan was gifted England’s seventh-minute opener by a howler from goalkeeper Patricia Morais, who slashed a kick out straight at the England striker. Duggan was rapped on the legs by the ball, but confidently brought it under control and fired in from 25 yards.
On 17 minutes ponderous defending allowed Carolina Mendes to equalise, but England restored their lead in the third minute of the second half.