The Norwegian claimed victory ahead of Moreno Hofland (LottoNL-Jumbo) and Roy Jans (Wanty Groupe Gobert) at Naseem Park on a stage covering 176.5km.
Edvald Boasson Hagen of Dimension Data continues to lead the way overall after finishing among the pack despite several heavy rainstorms in the Middle East.
“Wins are wins and at the end everyone is counting, saying ‘16 wins is worse than 20 last year’ or something, so this counts also,” said Kristoff. “It’s not a small race, it’s a hors categorie race and there are good riders here, good sprinters, it counts for something.
Tour of Oman
Nibali secures overall victory in Oman
“There’s still (Andrea) Guardini, [Sam] Bennett’s not slow, he won the last stage in Qatar last year, and there are other sprinters too.
"So there are still fast guys here and I still have to go at my maximum to beat these guys.”
The Tour continues on Friday with the climb to Green Mountain that should alter the general classification.
The race finishes on Sunday.
Results stage three
1. Alexander Kristoff (Nor) Katusha
2. Moreno Hofland (Ned) LottoNL-Jumbo
3. Roy Jans (Bel) Wanty-Groupe Gobert
4. Mike Teunissen (Ned) LottoNL-Jumbo
5. Jean-Pierre Drucker (Lux) BMC Racing
6. Zico Waeytens (Bel) Giant-Alpecin
7. Berden De Vries (Ned) Roompot-Oranje Peloton
8. Robin Stenuit (Bel) Wanty-Groupe Gobert
9. Daniel Oss (Ita) BMC Racing
10. Edvald Boasson Hagen (Nor) Dimension Data - same time
General classification after stage three
1. Edvald Boasson Hagen (Nor) Dimension Data
2. Vincenzo Nibali (Ita) Astana at 4 secs
3. Greg Van Avermaet (Bel) BMC Racing at 6 secs
4. Romain Bardet (Fra) Ag2r La Mondiale at 6 secs
5. Serge Pauwels (Bel) Dimension Data at 8 secs
6. Rui Costa (Por) Lampre-Merida at 10 secs
7. Jakob Fuglsang (Den) Astana at 10 secs
8. Domenico Pozzovivo (Ita) Ag2r La Mondiale at 10 secs
9. Davide Rebellin (Ita) CCC Sprandi Polkowice at 10 secs
10. Patrick Conrad (Aut) Bora-Argon 18 at 16 secs
Tour of Oman
Boasson Hagen strikes again