The Colombian climber said that he was still short of the levels of form of his rivals on the climb to Mount Etna, but said he hoped to have better legs come the second summit finish on Sunday.
"My objective on the first mountain stage was to be with my rivals and not to lose any time to them," Quintana told AS (opens in new tab).
"I'm lacking in race pace a lot, and I'm still not on the same level as my rivals. But it was the first serious day in the mountains and these early stages that precede the Blockhaus [stage nine's summit finish] will help me get up to speed."
Watch: Giro d'Italia stage four highlights
Lacking in form himself, Quintana was left to rely on his team-mates to chase down moves from the other GC contenders, giving particular praise to the work of Andrey Amador.
"Andrey was at the front of the peloton to control [Nibali's] attack, and I was able to stay in the wheels," Quintana continued.
"The team has been very good through all of the stages so far. Not just Amador, I'm very pleased with how the whole team is working here."
Quintana should be able to enjoy a relatively relaxing next few days, with few climbs to test the legs of the GC contenders before the Blockhaus on Sunday.
Thank you for reading 5 articles this month* Join now for unlimited access
Enjoy your first month for just £1 / $1 / €1
*Read 5 free articles per month without a subscription
Join now for unlimited access
Try first month for just £1 / $1 / €1
Henry Robertshaw began his time at Cycling Weekly working with the tech team, writing reviews, buying guides and appearing in videos advising on how to dress for the seasons. He later moved over to the news team, where his work focused on the professional peloton as well as legislation and provision for cycling. He's since moved his career in a new direction, with a role at the Department for Environment, Food and Rural Affairs.
Nairo Quintana disqualified from Tour de France after twice testing positive for tramadol
The Colombian will still race at the Vuelta a España because it is not considered a doping violation
By Ryan Dabbs • Published
We took nine cheap road tyres to a rolling resistance testing facility and this is how they stacked up
Here nine budget tyres are through their paces - including a trip to Silverstone Sports Engineering Hub to test their rolling resistance
By Luke Friend • Published