The Frenchman knew he had to distance Josef Cerny (CC Polsat) and Michael Rodriguez Galindo (Colombia) and paced his effort after he watched them lose contact on the climb to the finish.
Bouet finished 20th on the stage, 2:23 behind Siutsou but was four minutes ahead of the young Colombian, while Cerny cracked early and lost 12 minutes.
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"I'm happy to have the leader's jersey back. I like this race," he said after the stage.
I could have stayed with the leaders longer but after seeing that the other guys had been dropped, I eased off a bit and rode a paced effort, like a time trial. It was the right thing to do."
Bouet leads Siutsou by 3:19, with Bradley Wiggins (Team Sky) fourth at 3:48 and Vincenzo Nibali (Astana) fifth at 3:57.
"I lost two minutes today but overall victory is still possible. I think it's possible to defend the jersey. I believe in destiny," Bouet said, knowing that Friday's mountain finish will be decisive.
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"Tomorrow is up and down all day. A break could go and stay away. Me and my team will have to be control who gets in the break. On Friday it'll be up to me and my legs to see if I can win. Everything could be decided by a few seconds."
"A place on the final podium would also be a good result for me. We've also got Pozzovivo for the GC, so we've got two cards to play."
Bouet picked Siutsou as his biggest threat.
"He's strong, perhaps as much Wiggins," he said.
"I think Nibali is strong too. He might be thinking of Liege-Bastogne-Liege and so might not be here for GC, while Siutsou could be going for the overall GC for Sky."
Wiggo watching
Bouet got a close up view of the Nibali-Wiggins battle. He was impressed by both riders.
"Wiggins is strong. He could win races but hasn't won yet. It's like he's waiting and training," he said.
"With five kilometres to go today, I was next to him and he was spinning his gear really easily. He's not showing how good his form really is. But he could win if he wanted to."
Stephen is one of the most experienced members of the Cyclingnews team, having reported on professional cycling since 1994. Before becoming Editor-at-large, he was Head of News at Cyclingnews. He has previously worked for Shift Active Media, Reuters and Cycling Weekly. He is a member of the Board of the Association Internationale des Journalistes du Cyclisme (AIJC).
