Etixx rider Terpstra, who had been leading since winning the third stage time-trial, finished 6sec ahead of Poland’s Maciej Bodnar with Norway’s Alexander Kristoff, winner of three stages, third at 9sec.
“I’m happy to begin (the season) in good form,” said Terpstra, winner of last year’s Paris-Roubaix. “I know I don’t have to worry about that (form) so that gives me confidence.”
Bennett, of the Bora Argon team, took his first Qatar stage win in a sprint finish ahead of Italy’s Andrea Guardini and France’s Nacer Bouhanni after the 113.5km run from Sealine Beach to Doha.
For Etixx, formerly the Omega Pharma team, it was an eighth win in the past ten editions of the race.
The race went down to the wire with Kristoff just 11sec behind Terpstra at the start of the final stage.
“We were too tired in the end and the team couldn’t manage to put me in a good position,” said the Norwegian rider.
“I can’t be disappointed though with three stage wins. Terpstra was too strong in the time-trial, he deserves his win.”
Belgium’s four-time winner Tom Boonen — 2006, 2008, 2009, 2012 — and holder of a record 22 stage wins in Qatar returns home empty handed from the Emirate for the first time since 2004.
Results from the sixth and final stage of the Tour of Qatar over 113.5km from Sealine Beach Resort to Doha on Friday:
1. Sam Bennett (IRL/BOA) 2hr 24min 03sec, 2. Andrea Guardini (ITA/AST) same time, 3. Nacer Bouhanni (FRA/COF) s.t., 4. Peter Sagan (SVK/TCS) s.t., 5. Youcef Reguigui (ALG/MTN) s.t., 6. Adam Blythe (GBR/OGE) s.t., 7. Matteo Trentin (ITA/EQS) s.t., 8. Tom Boonen (BEL/EQS) s.t., 9. Jasper Stuyven (BEL/TFR) s.t., 10. Jose Joaquin Rojas (ESP/MOV) s.t.
Final overall standings
1. Niki Terpstra (NED/EQS) 17hr 36min 48sec, 2. Maciej Bodnar (POL/TCS) at 6, 3. Alexander Kristoff (NOR/KAT) 9, 4. Ian Stannard (GBR/SKY) 12, 5. Greg Van Avermaet (BEL/BMC) 19, 6. Peter Sagan (SVK/TCS) 31, 7. Luke Rowe (GBR/SKY) 33, 8. Heinrich Haussler (AUS/IAM) 39, 9. Tom Boonen (BEL/EQS) 39, 10. Andriy Grivko (UKR/AST) 41
– Agence France-Presse