No rider in the break was in a threatening position in the GC, meaning Rafael Valls (Lampre-Merida) wins the overall.
Brändle attacked inside the finale and none of his breakaway companions were able to follow, with Iljo Keisse (Etixx-Quick Step) having to make do with second.
Along with Brandle and Kiesse, Danny Pate (Sky) and Jef Van Meirhaeghe (Topsport Vlaanderen) all attacked early on the stage to make it into the day’s break.
Riders appealed to race officials after high temperatures caused dangerous conditions for the riders on stage four of the Tour
The peloton did not seem intent on chasing them down, allowing a gap of over nine minutes to materialise before starting the chase in earnest. Closing it proved too big a task for the peloton, and by the time only fifteen kilometres remained, the gap stood at around three and a half minutes and the break seemed certain to survive to the finish.
Behind them, Peter Sagan (Tinkoff-Saxo) won the sprint for fifth place, and may in hindsight rue allowing the break to survive.
There was some action in the GC as third place overall Alejandro Valverde (Movistar) put in a tentative attack on the final lap, but the terrain was not difficult enough to aid such efforts, meaning Valls hung on comfortably to seal the overall win.
For the Spaniard it is a first ever overall win, and by far the best result in his career. It will be interesting to see how he manages to compete with the big names as the season progresses.
Tour of Oman 2015, stage six: Oman Air to Muttrah Promenade, 134km
1. Matthias Brandle (Aut) IAM Cycling in 03-02-31
2. Iljo Keisse (Bel) Etixx-Quick Step at 0-04
3. Jef Van Meirhaeghe (Bel) Topsport Vlaanderen at 0-13
4 Danny Pate (USA) Sky at 0-16
5 Peter Sagan (Svk) Tinkoff-Saxo at 1-16
6 Ramon Sinkeldam (Ned) Giant-Shimano
7 Nacer Bouhanni (Fra) Cofidis
8 Alexander Kristoff (Nor) Katusha
9 Alexey Lutsenko (Kaz) Astana
10 Sam Bennett (Irl) Bora-Argon 18 all st
Final overall classification
1. Rafael Valls (Spa) Lampre-Merida
2. Tejay van Garderen (USA) BMC at 9 secs
3. Alejandro Valverde (Spa) Movistar at 19 secs
4. Rafal Majka (Pol) Tinkoff-Saxo at 32 secs
5. Jacques Janse van Rensburg (RSA) MTN-Qhubeka at 1-04
6. Louis Meintjes (RSA) MTN-Qhubeka at 1-08
7. Jakob Fuglsang (Den) Astana at 1-10
8. Ben Hermans (Bel) BMC Racing at 1-15
9. Julian Arredondo (Col) Trek Factory Racing at 1-25
10. Patrick Konrad (Aut) Bora-Argon 18 at 1-36