After three years competing for the Italian team, in her best-known victory, she won England's Hermes Grand Prix in Goodwood aboard her mount Adrett in July 1991 and again in May 1992.

In her first attempt at the age of twenty-two, she won England's Hermes Grand Prix Dressage competition in Goodwood aboard Adrett on July 5, 1991.

Pia noted in interviews that though her team scores may have been better if she had competed for her native Germany, a country far more dominant in equestrian sports, she had no regrets riding for Italy.

[2][3][4] Although she placed out of medal contention, her Olympic placings and mounts for dressage included: Pia rode for Italy's well respected Club Centro Ippico Monzese, affiliated with the Italian National Olympic Committee, where students learned not only to ride a horse, but to "respect, love and forge a relationship with the horse", a concept central to the creation of top competitors in dressage.

Lammers was considered one of the defining personalities in Westphalian (Westphalia region, Germany) equestrian sport, which he helped shape and supervise as state trainer for dressage for almost a quarter of a century.

Receiving around 100 medals as a trainer, the Equestrian Association of Westphalia honored Lammers' work with the Golden Plaque of Merit in 2002.