Darkhorse Mark Reyes continued his giant-killing run, ousting last year’s runner-up, Patrick John Tierro, in the semifinals of the Philippine Columbian Open Association (PCA) Open at the PCA shell-clay court in Paco, Manila.

Reyes, a Filipino based in Italy, made use of his powerful forehands to oust the second-seeded Tierro, 6-1, 5-7, 6-2, after almost two hours and 30 minutes.

The win put Reyes to a championship date with either defending champion Johnny Arcilla or top junior netter Francis Casey Alcantara, who were playing their semifinals match at presstime.

Arcilla is shooting for an unprecedented fifth PCA men’s singles crown while Alcantara is eyeing a first finals appearance in this annual tournament.

The left-handed Reyes dominated the first set but lost a 4-1 lead in the second set where the veteran Tierro seemingly gained his true game to force a deciding set.

In the final frame, Reyes regained steam and broke Tierro’s serve three times to complete the upset victory and move a step closer to the top purse of P100,000.

Meanwhile, the women’s singles semifinals will be played today with top seed Anna Christine Patrimonio facing No. 6 Jessica Agra and her younger sister, Anna Clarice, meeting last year’s bridesmaid and four-time champion Czarina Mae Arevalo.