The Belgian out-sprinted Sagan at the end of the 210km stage in Cepagatti and, in doing so, took the lead in the General Classification from Zdenek Stybar (Etixx-QuickStep) with only one stage to go. These three riders are all within eight seconds of each other on the GC. Bob Jungels (Etixx-QuickStep) is in fourth place and still in contention for the overall, 21 seconds behind Van Avermaet.
An early breakaway of six riders built up to an advantage of three minutes and 50 seconds over the peloton at 150km to go to ensure it was a long, tough day in the office for all riders on Stage 6. Most of the chase work at the head of the peloton was done by ORICA-GreenEdge and Etixx-QuickStep.
With less than 150km to go, the pace intensified before the first passage over the finishing line in Cepagatti where Sagan gave it all to win the second intermediate sprint of the day.
Sagan’s rush formed a group at the front which included his team-mates Daniele Bennati and Oscar Gatto, three from Etixx-QuickStep, including Stybar, Matteo Trentin and Stage 3 sensation Fernando Gaviria, as well as former World Champion Michal Kwiatkowski (Sky) and Van Avermaet.
With 15km to go, Vincenzo Nibali (Astana) tried to escape from the bunch, accompanied by Jan Bakelants (AG2R La Mondiale), but he didn’t bridge the gap. It went down to an uphill sprint finish won once again by Van Avermaet over Sagan who claimed the 69th second place of his pro career.
"It was a really nice finish for me as it was a little bit uphill. When I saw the parcours I knew it was a good stage for me. We tried to go for the bonus seconds on the first lap of the circuit and then we kept on going,” said van Avermaet after his win.
“The riders from Tinkoff and Etixx-Quick-Step worked really hard together to keep the gap on the peloton and I could save myself a little bit because we had Tejay van Garderen and Damiano Caruso behind us.
"I just tried to go as hard as possible in the sprint and it was just enough to beat Sagan. It's hard to beat him so I'm happy I could do it. I know I'm strong in a finish like this and I timed my sprint pretty well."
Van Garderen got caught in a crash five kilometres before the finish line. While he didn’t hit the tarmac, he broke a spoke and needed a wheel change, losing time on the general classification as a result.
Van Avermaet now faces one last battle to retain the leader's jersey during tonight’s final stage with a flat 10km ITT through San Benedetto Del Tronto.
"I'll try to do a good ITT tomorrow but it's not my specialty,” he said. “I'm in good form and I hope to do a good time. It's a bit strange that I'm up here on GC for Tirreno-Adriatico but we have the opportunity so I will try to go for the win here.
“I had good 11th place last year. It’s only 10km long. I have never been in such a situation before and I’ll never be again. This is my only chance to win this race I’ve always liked. I hope to take this nice trophy home.”
With only a handful of seconds separating the top four on GC, van Avermaet will have his work cut out for him.
I’m trying to win Tirreno-Adriatico but it’s not easy,” said Sagan. “For sure Greg is up there for the final victory against Stybar. I’m up there too but there are others as well. We’ll all go flat out and we’ll count the times at the end.”