The Movistar rider finished 24 seconds in front of FDJ's Thibaut Pinot and Team Sunweb's Tom Dumoulin to take top spot from Luxembourg's Bob Jungels.

He attacked with 4.7km remaining on the 149km stage from Montenero de Bisaccia to Blockhaus.

Quintana leads second-placed Pinot of France by 28 seconds in the overall standings and third-placed Dumoulin of The Netherlands by 30 seconds.

Team Sky's Geraint Thomas and Orica-Scott's Adam Yates were both grounded in a crash at the foot of the final climb, where a police motorbike stopped at the side of the road caused a major pile-up.

Dutchman Wilco Kelderman was unable to avoid it, hitting the officer with his shoulder before swerving to his right into the Sky riders in a line in the peloton.

Thomas appeared to be suffering from a right shoulder injury and stayed down for several minutes before being able to get back on his bike.

Having started the day in second place, he now finds himself 5min 14sec behind Quintana in 17th. 

"I'm a bit angry at the minute and need to work out what to do tomorrow," Thomas was reported as saying by BBC Sport.

"The bike had just stopped on the side of the road, we were all racing for position and someone in front of me hit it and we had nowhere to go.

"We all went straight down."

Thomas added: "I had felt good and then I crashed and my race was over. 

"It is very disappointing."

Yates, meanwhile, has dropped from third position to 16th, 4:49 off the pace.

Defending champion Vincenzo Nibali of Italy finished in fifth place today, 59 seconds behind Quintana.

The Bahrain-Merida rider is also fifth overall, 1:10 back.

The Netherlands’ Bauke Mollema of Trek-Segafredo is 51 seconds behind in fourth having finished in the same position today.

The 10th stage is scheduled for Tuesday (May 16) following a rest day tomorrow.

It will see riders undertake a 39.8km individual time trial from Foligno to Montefalco.

Action concluded today at the women's Tour of California as The Netherlands' Anna van der Breggen pipped the United States' Katharine Hall to overall victory.

Van der Breggen, the Rio 2016 Olympic road race champion, beat her American counterpart by just one second.

It came after she took intermediate sprint bonus seconds on the last two days of the four-stage race.

Cuba's Arlenis Sierra finished third in the overall standings, 31 seconds off the pace. 

Italy's Giorgia Bronzini won today's 70km final stage in Sacramento, edging out the US's Coryn Rivera and The Netherlands' Kirsten Wild.

Sacramento also hosted the 167.5km opening stage of the men's race today, which saw Germany's Marcel Kittel outsprint Slovakia's Peter Sagan to claim his first win at the Tour of California.

Italy's Elia Viviani rounded out the top three. 

Stage two is scheduled for tomorrow and will see riders undertake a 144.5km route from Modesto and San Jose.