Ri Ye Rim begun the scoring for the defending champions, firing in from close range in the ninth minute after Ri Ui Gyong's cut-back had been intercepted.

They doubled their advantage in the 29th minute when a loose ball in the box fell for Yu (pictured above) who smashed in via the post.

Partner-in-crime Kim Won Sim then got in on the act when she sent an outrageous outside-the-boot effort into the top-left corner 40th. Kim was on-hand again in added time to hammer home a Ri Ye Rim cut-back for 4-0.

Poland could have been forgiven for going into their shells in the second half but came out fighting and pulled a goal back almost immediately.

Zofia Burzan's slide tackle saw the ball fall to Nicola Galuszka 25 yards out, and the substitute sent a scorching first-time effort into the top corner just after the restart.

It wouldn't begin a comeback, however, as Yu headed in from a corner in the 53rd minute to notch her 12th tournament goal and surpass Venezuela's Deyna Castellanos as the tournament's all-time top scorer.

Ri Ui Gyong then stole in to volley home the goal her performance merited in the 58th.

Having confirmed their knockout stage spot, DPR Korea only need a draw with Nigeria on Friday to finish as the Group B winners.

Photos: FIFA via Getty Images