The New Saints impressed as they held Swedish champions Helsingborg to a goalless draw in the Champions League second qualifying round at Park Hall.
They dominated for long periods but were unable to take advantage despite living up to boss Craig Harrison's hope that they would not be overawed.
New signing Chris Jones was on target on several occasions, hitting a post on one one of them, but all to no avail.
TNS travel to Sweden for the second leg on Wednesday 25 July.
Helsingborg's previous appearance in the Champions League in 2000-01 saw them beat Inter Milan to reach the group stages.
They held Bayern Munich to a draw in Germany and also drew at home to Paris St Germain and beat Rosenborg.
More recently they reached the last 32 of the Uefa Cup in 2007-2008 and have a number of internationals in their current squad.
TNS reached the Champions League third qualifying round in 2010 before losing 6-1 on aggregate to Anderlecht.