«We’ve been trying pretty much all seven days now that we’ve been here and I’m just so happy to repay them with the win now,» Ewan told Cycling News.
«I thought if I was feeling good that I’d go first through the last corner, but it was still a long way to go and I wasn’t feeling that good.
«It was quite a hard final — harder than I thought it would be. I just waited. I knew I had a good kick so I just waited until he (Ackermann) went then I came around him.
«It means a lot. I have a lot of pressure on me to win races now. The difference now is I’m expected to win. I had an alright start to the year, but not a great one. To win here means the world to me.»
The Lotto-Soudal rider’s Australian teammate Adam Hansen, who finished 101st, said Ewan’s win was spectacular.
«The last 40km were very technical with twists and turns so the idea was to protect him in the hope that he could come to the finish feeling fresh and that he could finish it off,» Hansen said.
«We came here with one goal with Caleb. Now we have that first win so we can relax.»
Ewan is third in the points classification rankings with 91, behind Arnaud Demare’s with 98 and the leader Ackermann with 150 points.
Meanwhile, Italian Valerio Conti of Team UAE retained the overall leader’s pink jersey with Spanish Movistar rider Jose Rojas one minute and 32 seconds behind.
Italian Giovanni Carboni, riding for Bardiani CSF, is nine seconds behind Rojas in third place.
Australian Team Mitchelton-Scott’s star Simon Yates, the 2018 Tour de France winner, remained almost six minutes back from Conti in 15th place.
The best placed Australian rider is Dimension Data rider Ben O’Conner in 36th, while Bora-Hansgrohe’s Jay McCarthy is in 43rd.
Mitchelton-Scott’s Lucas Hamilton is in 51st, while Team Sunweb rider Jai Hindley is seven places back and Hansen is in 67th.
Hamilton’s teammate Luke Durbridge is 70th, while Team Sunweb’s Christopher Hamilton is 73rd and Ewan is 114th.
The remaining Australians are Miles Scotson in 156th, Mark Renshaw two places behind him and Will Clarke in 162nd.
Sunday’s ninth stage is a 34.8km individual time trial from Riccione to San Marino featuring a 12.25km climb at the end.