By ESPNSTAR.com staff
Hartmann opened the scoring after just five minutes when he slotted into an empty net after an incisive pass from Andres Gonzales, before he turned provider in the 32nd minute by swinging in a corner for Jeong Byeong-yeol to head home.
The 20-year-old then laid on another assist in the 69th minute when his left-wing cross was met with sweetly-struck volley by Phil Younghusband into the back of the net and seven minutes later, he grabbed his second of the game to all but end the contest.
There was still time for Hartmann to complete his hat-trick, which came in the 80th minute following an impressive passing move by Loyola, capping off a fine day at the office for Kim Chul-su's men.
The Sparks will next meet reigning United Football League champions Global, who saw off Kaya with a 2-1 extra-time victory on Tuesday evening.
Green Archers United are also through to the last four after seeing off Pachanga 4-3 on penalties, after both sides played out a 1-1 draw.
Green Archers opened the scoring after just six minutes when Jesus Melliza found the back of the net, but they were pegged back eight minutes before the half-hour mark by Ariel Zerrudo.
And with neither side able to add a second goal, the game then went to the dreaded penalty shoot-out, where early misses from Pachanga duo Alfredo Razon Gonzalez and Jason Cunliffe set the stage for Ayi Nii Aryee to sink the Archers' fifth effort and send them through to the semis.
Standing in between them and the final are Stallion, who advanced from the quarter-finals with a 5-4 shoot-out win over General Trias International, after their game had ended in a 0-0 draw.
Thursday's UFL Cup Quarter-final Results
Loyola Meralco Sparks 5-0 Philippine Army
Stallion 0-0 General Trias International (5-4 on penalties)
Green Archers United 1-1 Pachanga (4-3 on penalties)
Tuesday's UFL Cup Quarter-final Results