Viviani, the only one of the world's elite sprinters competing at the Giro, proved once more that he is a class above, sitting on the wheel of Irish sprinter Sam Bennett and avoiding a close call with the barriers before powering past in the final metres to go back-to-back. For a second consecutive stage young Jakub Mareczko (Wilier-Triestina) sprinted well but was unable to produce expert timing.
"I think Viviani, he sprinted but he didn't go full", admitted Dennis.
Sunday saw a three-man breakaway go clear nearly right from the start with Canadian Guillaume Boivin making it into the escape group for the second day in a row.
"But I felt better later and I knew that I was the favourite at the finish".
"I have chosen to do the Giro this year".
After three days racing in Sicily, the Giro will move onto the Italian mainland, although not before the overall contenders have had a chance to test themselves on a summit finish at Mount Etna, the highest active volcano in western Europe.
Dennis has now worn the leader's jersey at all three Grand Tours, following opening stage success at the Tour de France in 2015 and last year's Vuelta a Espana.
Palestinian protesters shoot down Israeli drone with stones
A military spokeswoman said that some of the protesters threw stones at the Israeli forces . Someone has well said that everything is made in China, but courage is made in Palestine.
Dennis now leads by one second from Dumoulin with Belgian Victor Campenaerts third at 3sec.
"It's a special feeling to have the Maglia Rosa".
After a rest day the Giro participants on Tuesday, will overcome the first stage in Italy.
"Rémi [Cavagna] took the responsibility on his shoulders and closed the breakaway, Styby [Zdenek Stybar] brought us to the front, then Florian [Sénéchal] took over with two kilometres to go before Michael [Mørkøv] and Saba [Fabio Sabatini] dropped me in the closing kilometre".
"They took to the race really well and supported us like they were a really big cycling country, which was really nice", he said. Here it's been the complete opposite.
The peloton seemed relaxed as it departed Be'er Sheva with a trio managing to escape pretty easily consisting of Guillaume Boivin (Israel Cycling Academy), Enrico Barbin (Bardiani-CSF) and Marco Frapporti (Androni-Sidermec).
The race was the third and final stage to be held in Israel.
Esteban Chaves and Simon Yates of the Australia-based Mitchelton-Scott team finished 15th and 16th respectively.