The seven-wicket loss for Central Punjab means the Babar Azam-led side bow out of the competition with just one win in five games.
Fakhar remained unbeaten during Khyber Pakhtunkhwa's pursuit of the steep 178-run target as he held onto one end firmly and steadily kept the scoreboard ticking along.
The left-handed opening batsman brought forth a ravishing display of classy strokes in his 54-ball 82, smashing seven boundaries and two maximums.
Khushdil, who earned a maiden call-up to the national side on Monday, forged a breezy 72-run stand with Fakhar after Iftikhar Ahmed's wicket threatened to stall their progress.
The 24-year-old belted two sixes on consecutive deliveries off Faheem Ashraf in the final over of the game to surmount the daunting target and take his vital contribution to 46 not out from 26 balls.
Earlier in the virtual knockout, Central Punjab rode on stunning half-centuries from Babar and Umar Akmal to lift the side's total to 177-3.
Babar, the newly appointed Pakistan T20 skipper, blasted four sixes as he scored 83 runs only to be run out in the last over of the innings.
Babar's dazzling stay at the crease saw him bring up his 13th 50-plus score in T20 cricket this year – a new record for a Pakistan batsman.
Umar, who perished for successive golden ducks in the Sri Lanka T20 series, also hit four sixes as he made 53 off 37 deliveries.
Sindh is the other team that failed to qualify for the semi-finals, which are due to take place on Wednesday.