It was announced last night that Williamson would head to Sweden in May to compete with the world's best reinsmen in the week-long series.
Williamson described his selection as a great honour.
''It is a very exciting opportunity and it will be a great honour to represent the country.''
He will compete in 24 races at five racetracks across Sweden.
A total of 12 world-class drivers will compete in the series.
The championship is likely to be the highlight of the reinsman's working year, but not top of his personal triumphs in 2019.
His partner and fellow driver, Charlotte Purvis, is expecting their first child in June.
Few would be better credentialed to represent New Zealand in the series, as all events in the competition are trotting races.
The 27-year-old hopes to get the chance for a close look at how the Swedes fine-tune their squaregaiters during the week.
''That is going to be a good thing and I think we get a couple of days off during the week.
''So even just seeing how they do things over there [will be good].
''I have been in the junior drivers series a couple of times ... They are really good trips for everything you take in and the people you meet.
''When you go overseas it is good to go and see how everyone else does it.''
He said he could not have been picked without support from New Zealand owners and trainers.
''...I owe them a big thanks.''
It is a case of back to reality for Williamson after the thrill of last night's announcement.
He will be busy at Forbury Park tonight, with nine drives.