Viviani holds a two-second advantage going into Saturday's final stage of the event.
Elia Viviani retains lead of Dubai Tour as Sonny Colbrelli wins Stage 4 at Hatta Dam
Elia Viviani retained the blue jersey to lead the Dubai Tour with just one stage to go after finishing sixth in Friday's fourth stage as Italian Sonny Colbrelli won the stage.
Colbrelli prevailed from Magnus Cort Nielsen and Timo Roosen to win the 172km stage, which ran from Skydive Dubai to Hatta Dam.
Colbrelli said after triumphing: “I really wanted to win today because the team has been working for me since day one. I was close yesterday. Today, again, Bahrain-Merida has done a great job.
"I launched the sprint from very far out because I had a mechanical and I was stuck on the 53. I couldn't wait for this race to end. The last 50 metres looked to me like an infinity. This victory means a lot for my team and is very important for my morale. Even without being the favorites, we raced as a team like leaders."
Viviani holds a two-second lead from Cort ahead of Saturday's Stage 5, the Meraas Stage, which is 132km in length.
Despite holding the lead, the Italian is taking nothing for granted.
He said: “The race isn't over yet. Two seconds advantage over Cort Nielsen isn't much, considering how strong he is ... but we have a strong team. It was the case again to close the gap on the breakaway riders.
"I'm happy with the result because the goal was to defend the Blue Jjersey. I think I couldn't do more than this. When Colbrelli went, I thought my legs were dying. I just have to do my best sprint tomorrow to win the Dubai Tour and possibly another stage.”
Stage 5 starts at 12.20pm and runs again from Skydive Dubai, with the finish on the City Walk.