He won the road race at the 2000 World Cycling Championship in Plouay, France.

At the end of the 268.8 km (167.0 mi) race, he won the sprint for the line ahead of Zbigniew Spruch and defending champion Óscar Freire.

[1] Following his world title, Vainšteins moved to the Domo–Farm Frites–Latexco team under Patrick Lefevere.

Even with some impressive results, such as third place in the 2001 Paris–Roubaix, he was unable to follow up on the success of his world championship.

He left the team after the 2002 season and raced with Vini Caldirola and Lampre for two more years before retiring.