The Flying Dutchmen (17-4-2 overall) advanced at the Waverly, Iowa, Regional to face host Wartburg College in Saturday's second round. Kickoff is 5 p.m. Central Standard Time.
Sikkenga struck first for Hope. The junior back from Hudsonville (Hudsonville HS) scored off a throw-in 12 minutes, 37 seconds into the match. Senior back Grant Neil of Holland (West Ottawa HS) had the first of his two assists for the match.
It was Sikkenga's seventh goal of the season.
Neil helped the Flying Dutchmen extend their lead to 2-0 in the 54th minute when he set up senior Matthew VanZytveld of Grand Haven (Grand Haven HS) for his second goal of the season.
That was enough for Hope goalie Ethan Beswick. The sophomore from Grand Haven (Grand Haven HS) stopped two of the three shots he faced. Wisconsin-Oshkosh (16-2-4) scored in the 87th minute.
Wartburg (16-4-2 overall) blanked Dominican (Ill.) 4-0 in Friday's first match.
Michel Levine put the Knights on the scoreboard with his second goal of the season in the 31sst minute. Wartburg then scored three times during the second half.
Chris Nothnick, Peter Tran and Paris Martins chipped in goals for Wartburg. It was Martins' eighth this season, Nothnick's second and Tran's first.