Former world champion Rui Costa (UAE Team Emirates) attacked early on the final 11km climb of Jebel Hafeet to ultimately clinch the stage win and overall race lead.
Portuguese rider Costa was joined by Russian climber Ilnur Zakarin (Katusha-Alpecin) as they distanced the likes of Nairo Quintana (Movistar), Vincenzo Nibali (Bahrain-Merida), Alberto Contador (Trek-Segafredo) and Fabio Aru (Astana).
The lead pair worked well together, with Costa edging ahead of Zakarin among the craggy rocks of the desert mountain.
Tom Dumoulin (Team Sunweb) had put in a concerted chase to try and catch the leaders, but had to settle for third place.
The 2017 Abu Dhabi Tour concludes on Sunday with a stage that looks likely to finish in a bunch sprint. Barring disaster, Costa should finish in the peloton to take the overall victory.