Australia's Ben O'Connor has savoured his first "super easy" day as a Grand Tour race leader, losing only six seconds of his advantage in stage seven of the Vuelta a España.

O'Connor and countryman Jack Haig were among the leading pack at the conclusion of the 180.5-kilometre stage from Archidona to Córdoba, with Belgian Wout van Aert coming out on top in a sprint finish.

O'Connor, riding for Decathlon-AG2R La Mondiale, lost only six bonus seconds to his nearest rival Primož Roglič, who won an intermediate mountain sprint.

"It was a super easy day until the finale, which was explosive," O'Connor said after the stage.

"I wasn't surprised Primož went for the bonus, but it wasn't a crazy, explosive attack on the climb, so I was pretty comfortable at how I felt today and happy with the way it turned out.

"I guess every single little bit [of time won back] counts [for Roglič] and I can't really do much against Primož's strength for the bonuses.

"But you have to take a lot of bonuses to make up that amount of time. All in all, a good day."

O'Connor said wearing the leader's red jersey felt like "the biggest reward in my career".

"It feels good and it looks good as well, so hopefully I can wear it for quite a few days to come," he said before the start of stage seven.

Fellow Australian Kaden Groves, winner of stage two, crashed 25km from the finish after clipping Nairo Quintana's back wheel.

Groves (17 points) sits in second place in the points classification, with Spain's Xabier Isasa (20 points) on top.

AAP/ABC