Haas (Dimension Data) has shown terrific form this season, despite not yet having won a race by the end of Thursday's sixth stage. The 28-year-old senses he is on the cusp of a breakthrough win in Saturday's 189-kilometre stage from Molfetta to Peschici, but he also knows it will only be a matter of time before his good form, which has driven him since he finished third at the Australian road championships in January, deserts him.

Haas knows the hilly route of stage eight plays to his strengths. "That one [course] that suits me the best," Hass said of the route.

The stage includes two categorised climbs - the Monte Sant'Angelo and Coppa Santa Tecla - plus several uncategorised hills before the riders are faced with a steep uphill finish.

The course is tailored for Haas who relishes racing in breaks, climbs hills well and has a nifty sprint against a smaller group.

Such a scenario presented itself on Sunday's third stage from Tortoli to Cagliari in Sardinia when he and six others escaped in cross winds in the last 10km, but then saw him fall short after he launched the sprint early on which the Colombian flyer Fernando Gaviria (Quick-Step Floors) swept by to win.

However, Haas, who placed fourth on that stage, said that Saturday could offer a better opportunity, anticipating that its added climbs should eliminate Gaviria from the equation.

"That's my bread and butter," Haas said of racing on courses like Saturday's. "That is what I feel my body is made to do.

"You have to fight all day. Then you have a really hard finish and normally by then you've gotten rid of guys like Gaviria."

It's a valid plan, but harder to follow through with should condition suddenly wane. It has amazed Haas that he has kept his form in a season that began with third in the Australian road title. He then claimed one second, two fifths and a ninth in stages of the Tour Down Under in South Australia and fourth overall; seventh in the Cadel Evans Great Ocean Road Race in Victoria; fifth, fourth, and ninth in stages of the Tour of Oman and 10th overall; and a best World Tour finish of fourth in the Dutch Amstel Gold Race on April 16.

"I can't believe I've held the form since nationals, but I am going to break through whatever it is. I'm not giving up until it happens," Haas said after Wednesday's fifth stage from Pedara to Messina in Sicily, when he admitted that some cracks were starting to emerge after a "miserable" day on the bike in which Gaviria again won, but in a bunch sprint.

"I think either my allergies have got bad or it has turned into a little bit of ill health," Haas lamented. "That's the kind of issue when you race full gas from January 1 - any small little thing can really knock you for six. I am not feeling great ???"

Citing Wednesday's stage as an example, he said: "My mind was too tired to make the right decisions. I felt every time a gap opened up, someone else filled it," adding that it was even harder in bunch sprint finishes such as Wednesday's. "It's hard to engage in those final kilometres," he said. "You can buy-in to the finals only a few times when the mind isn't hungry for it. I am struggling a bit, but I have quite a bit of gold left in the legs. It's just how gold that is going to be."

At Thursday's stage start, Haas said he was even feeling better. But afterwards he posted on Twitter: "Some days you are the Hammer, the other the Nail. Today felt like neither. More like my legs had nails inside! Hoping things come around L"

If they do, who knows what Saturday's stage will bring him.

Fact File
The 100th Giro d'Italia

A crucial four days
Saturday: Stage 8 - Molfetta to Peschici, 189km
Sunday: Stage 9 - Montenero di Bisaccia to Blockhaus, 149km
Monday: Rest day - in Montefalco
Tuesday: Stage 10 - Foligno to Montefalco, 39.8km individual time trial