Now enjoying a 22 second buffer to Costa, Hermans is all but assured overall victory with just one stage remaining; the run into Matrah Corniche, traditionally one for the sprinters.
Largely a domestique, Hermans has not won a stage race in his now nine-year professional career, his last win, the third stage of the Arctic Race of Norway in 2015. Defeating the likes of Aru and Costa on today's stage, Hermans was asked if the queen stage victory was the biggest win of his career.
"Against the riders that I faced here today, yes I think so," he said.
"It was really hard. Fabio Aru was just behind me at ten of fifteen metres so it was really fast right until the line. Kudus attacked and he was just ten seconds in front of me but I still had a good effort in my legs. After the victory on the second stage I had the confidence."
"It will be my first GC win. We still have to do one stage of course, but without bad luck I will win the overall.
"I never expected to have this kind of start to the year in Valencia (second overall) and here in Oman.
"I just wanted top tens in those races and now I have finished second in Valencia and will normally win this race so it's the perfect situation.
Kudus was understandably disappointed with how the finale unfolded but remained upbeat.
"When we hit the climb I was a little bit nervous but I think I did a great job in the end, the plan we had today was also very good and just gave it my best.
"Today was the main key stage and it was very hard. There was headwind and crosswind so the whole the day was stress in the bunch."
Other GC hopeful Romain Bardet (AG2R) was caught up in a crash with around 81 kilometres to go. While he said he had no excuses he did feel the pain stopped him from doing better than just hanging on in the final kilometres despite nomajor injuries. The Frenchman managed to still finish 10th and remains sixth on GC.
Earlier in the stage
After 22 kilometres raced, Mark Christian (Aqua Blue), Daniel Diaz (DMP), Oliver Pardini (WB Veranclassic), Jonathan Clarke (UHC) and Preben Van Hecke (Sport Vlaanderen) escaped from the bunch. With around 146 kilometres of flat terrain before Green Mountain arrived in the final six kilometres, the group easily built a maximum advantage of eight minutes.
Astana started to shut down the break by taking control of the race with 50 kilometres to go. Within the first kilometre of the final climb, the break was caught.
Australia's Lachlan Morton (Dimension Data) then attacked but despite initially putting in 20 seconds back to the bunch, he was caught by the main players with three kilometres to go.
Then it was team mate Kudus's time to launch, Hermans eventually coming around him with 750m to go, then Aru and Costa.