Villumsen, not satisfied with her ninth placing in the time trial in changeable conditions, produced a strong performance in the 182km road race, around 10 laps of a testing circuit at Ponferrado.
The race was shaped by a massive series of crashes, which led to a mass pile-up on the descent on the second lap.
Much of the field was either caught in or delayed by the incident, which caused several riders to be taken to hospital.
Villumsen regained contact but both Jo Kiesanowski and former Otago rider Reta Trotman were caught in it, along with many of the major teams.
Trotman had been brought down early, requiring a wheel change, and had only just caught up before she was held up behind the crash.
Kiesanowski had used her skills to avoid the crashes in front of her, only to be rear-ended by crashing riders and taken down.
The two New Zealanders were delayed several minutes and while they continued for several laps, they were finally pulled from the race with a group of riders by the commissaries.
Teammate Emily Collins withdrew earlier.
''It [the crash] changed the race a lot with many of the big countries with riders out, like us.
"The race did nothing really, while as many as possible were able to catch up, and only got into life on the last few laps,'' Villumsen said.
Villumsen sat back in the peloton in the early laps before moving closer to the front, using her skills to counter the tricky descent following a sudden heavy rain shower late in the race.
A lead group of four pushed clear on the final climb.
The New Zealander nestled in with some of the leading sprint hopes on the chase and caught the leading quartet 400m from the finish.
She looked for a way through in the dash for the line but found no gaps, finishing a bike length behind surprise winner Pauline Ferrand Prevot (France), who held off time trial winner Lisa Brennauer (Germany) and Emma Johansson (Sweden).
''I worked as hard as I could on the final climb and then I got blocked coming into the final straight about 400m from the finish,'' Villumsen said.
''I am not a sprinter so I don't have that speed.
"There's was nothing more I could do better.
"Any time you can finish in the top 10 in the world championships is a really good result.''
