The American conquered stage favourite Victor Campenaerts (Lotto Soudal) by four seconds, covering the 17km on the streets of Verona in 22:07.
A WorldTour professional since 2014, Haga rides mostly in the service of others particularly Tom Dumoulin more recently. A key part of the Dutchman's overall Giro d'Italia victory in 2017, Haga said losing the team's leader this edition added a bittersweet edge to his stage win.
"My victory is of course a consolation price after (Tom) pulled out," he said. "It’ll take a bit longer to realise but it’ll come. I came in top form but it was a support form.
"During the time trial, I kept thinking this is what Tom would have been doing today if he was here. I thought today I had a real possibility because the course suited me very well and for sure better than the one of Stage 9.
"As an American, I feel very proud of winning a stage at the Giro d’Italia.”
Known for his poetic Twitter posts during grand tours where he sums up each stage in one simple tweet (and therefore uses the hashtag #GIROversimplified for example) he offered a simple explanation for his win, telling Eurosport "I had to go really slow the last two weeks to go really fast today."
But he had more insight on the technically challenging course later for his team's website.
“It was a very fast course, with a lot of technical corners. The climb was very tough to pace, there was no rhythm on it and you had to constantly adjust your effort to the climb.
"The descent after the climb was very fast and technical. The extended recon I did for that paid off; I watched a video of it around twenty times this morning.
"After the last TT we knew this one would suit me more, so I’m very thankful for the team allowing me to save myself as much as possible over the last week for today.
"It’s been a hard Giro for us; we started well but then lost Tom, Rob (Power), Louis (Vervaeke) and Sam Oomen. Since then we have been trying to salvage anything from the race. The win means a lot to me but it also means a lot to the team too, it redeems the Giro for us.”
It's always nice to see the good guy get a win, but especially after Haga's 2016, an annus horribilis marked by tragedy undoubtedly forging the tears he wept after Carapaz crossed the finish line.
In January 2016, he and John Degenkolb were the worst affected - and lucky to be alive - when the pair and their Giant-Alpecin teammates were hit head-on by a car at a training camp in Spain. Haga was airlifted to hospital with deep gashes to his face and he still bears the scars prominently on and under his chin. His father died from non-smoking related lung cancer later that year.
