Weld's filly is toast of Curragh.
Carrying the familiar silks of Khalid Abdullah, the 5-1 shot travelled powerfully during a rough race before being asked to go about her business by Pat Smullen.
The response was emphatic as Tested quickly put daylight between herself and her rivals, coming home with a length and three-quarters in hand over Sparrow.
Weld said: "She's definitely a Stakes filly. It was a bit rough early on and she got buffeted about a bit, but Pat took his time and got her balanced.
"She's still very babyish. I'll speak with Lord Grimthorpe (Khalid Abdullah's racing manager ), but I doubt I'll run her again this year.
"There is a listed race back here in two weeks time (the Staffordstown Stud Stakes), but I think I'll probably run the Prince's filly who won in Listowel (Laynard) in that race."
Hot favourite My Titania was made to pull out all the stops as she claimed Group Three honours in the CL Weld Park Stakes.
The first foal of trainer John Oxx's incredible colt Sea The Stars to wear the same colours of owner Christopher Tsui, My Titania built on a promising Leopardstown debut to score at the second time of asking at the same venue.
Sent off an 11-10 market-leader, the youngster moved towards the front end stylishly in the hands of Declan McDonogh.
However, Chicago Girl and Johnny Murtagh came out of the pack to challenge and My Titania was all out to cling on by half a length.