Vekic arrived in the semifinals having already won four of her five matches in three sets, including her past three in a row.
She needed almost three hours to see off Australian Open semifinalist Dayana Yastremska in the third round, overcame Paula Badosa in an intense fourth-round clash, and rebounded from a set down to end the fairytale run of Kiwi qualifier Lulu Sun.
Her exertions became apparent in the second set, where she was managing forearm pain with ice as her shot speeds on that wing declined.
Somehow, she tapped into a well of physical reserves in the final set, but at certain points was visibly weeping as she dealt with pain, plus the challenge of a persistent Paolini.
Vekic ultimately saved two match points, but a third was beyond her.
“Sometimes it can help (releasing emotion on court). My tears were not because I was… I mean, I was more crying because I had so much pain, I didn’t know how I could keep playing,” Vekic revealed.
“I thought I was going to die in the third set. I had so much pain in my arm, in my leg.
“It was not easy out there, but I will recover.”
The former world No.19, currently ranked 37th, is projected to return to the brink of the top 20 in next week’s WTA rankings.