The Italian rider just edged past Pinot after he attacked with 300m to go. Fellow general classification contender, Rohan Dennis did well to stick with them but Montaguti timed his sprint just perfectly, coming round Pinot right before the line.
Geraint Thomas (Team Sky) rolled in outside the top-10 but had done enough to secure the leader’s jersey for the final day. However, Pinot’s second place puts him only 13 seconds behind the Welshman making for what will be an entertaining final stage.
The days action kicked off when Stefano Pirazzi (Bardiani), Simone Andretta (Bardiani), Davide Villella (Cannondale-Drapac) and Killian Frankiny (BMC) broke away from the peloton with 40km to go.
The unlikely bunch rode together as Frankiny turned up the pace but soon found themselves falling apart. Andretta was first to go and riders in the peloton could sense a weakness despite the riders holding a 1-07 lead.
Dario Cataldo’s (Astana) tried to make the jump to the break but with Team Sky in control of the overall standing and the peloton, Thomas was happy to let him go.
Cataldo was soon joined by Pinot, who after a poor showing the day before had some time to make up against Thomas. Current green jersey holder, Alexander Foliforov (Gazprom-RusVelo), forced an attack on the pair as they rolled over the day’s final classified climb of Forcella di Brez.
As the two breakaways descended, the peloton soon followed with Thomas lying safely in the midst of his teammates.
Thomas’ fuchsia pink jersey was a reminder at the front of the peloton for fellow overall rivals, forcing Michele Scarponi (Astana) to push himself on the descent.
The Italian rider forced himself to attack taking corners aggressively but soon crashed. Team Sky’s riding had baited other riders into attacks but a tricky descent made the peloton stick together.
As they closed in on the day’s breakaway riders, Team Sky were down to just two riders with 6km to go.
Mikel Landa sacrificed himself at the front of the peloton in an attempt to get Thomas in position. The move was almost a copy of their riding the day before. It wasn’t to be though as teams fought for position at the front with Thomas jumping from wheel to wheel.
A small uncategorised climb fell just before the finish proving to be a bridge too far for Frankiny and co after holding a lead of 1-27. With less than 2km to go, the peloton soon engulfed them.
As the riders poured into Cles, Pinot and Dennis positioned themselves for a sprint but a late surge from Matteo Matuigi took the win from both overall contenders.
The Tour of the Alps will continue on Friday for the final stage between Smarano to Trento.
Tour of the Alps 2017, stage four: Bolzano to Cles (165km)
1. Matteo Montaguti (Ita) AG2R La Mondiale, in 4-56-38
2. Thibaut Pinot (Fra) FDJ
3. Rohan Dennis (Aus) BMC Racing Team
4. Luis Leon Sanchez (Spa) Astana Pro Team
5. Jose Mendes (Por) Bora-Hansgrohe
6. Damiano Caruso (Ita) BMC Racing Team
7. Lawrence Warbasse (USA) Aqua Blue Sport
8. Iuri Filosi (Ita) Nippo – Vini Fantini
9. Matteo Busato (Ita) Willier – Trestina
10. Davide Villella (Ita) Cannondale-Drapac, all same time
General Classification after stage four
1. Geraint Thomas (GBr) Team Sky, 15-36-10
2. Thibaut Pinot (Fra) FDJ, at 13 secs
3. Domenico Pozzovivo (Ita) AG2R La Mondiale, at 16 secs
4. Michele Scarponi (Ita) Astana Pro Team, at 21 secs
5. Davide Formolo (Ita) Cannondale-Drapac, at 21 secs
6. Mikel Landa (Spa) Team Sky, at 26 secs
7. Hugh Carthy (GBr) Cannondale-Drapac, at 39 secs
8. Damiano Caruso (Ita) BMC Racing Team, at 42 secs
9. Pierre Rolland (Fra) Cannondale-Drapac, at 46 secs
10. Danilo Celano (Ita) Italy, at 48 secs