Former European 400m hurdles champion Rhys Williams has won his first race since serving a ban for failing a drugs test in July 2014.
The 31-year-old clocked a time of 53.45 seconds at the Welsh Athletics Regional Championships in Newport.
UK Anti-Doping found that Williams and fellow countryman Gareth Warburton had inadvertently taken a contaminated food supplement.
"It's been so tough but I'm glad it's behind me," Williams told BBC Wales.
"It's made me more determined, more mentally strong and I hope to use that to my advantage."
The Welsh athlete's next race will be in Belgium on Wednesday and he has his sights on a place in the Great Britain team for August's World Championships.
Williams would have to finish in the top two in the British Championships on 5 July to be selected.
Saturday's meeting at Spytty Park in Newport was Williams' comeback following a four-month ban.
Both Williams and Warburton had to withdraw from the 2014 Commonwealth Games, where Williams was set to be co-captain of Wales' athletics team.
Williams was subsequently cleared of knowingly cheating, but still had to serve the ban.