There were mixed fortunes for the Schnell siblings in their home hometown of Calgary where PSA World Tour regular Andrew Schnell went down in four games to Australian Rex Hedrick, but older brother Graeme Schnell - ranked outside the world top 300 - upset third seed Jan Koukal to claim a shock slot in the quarter-finals of the TAQA Bankers Hall Club Pro Am at the Canadian city's Bankers Hall Club.
Schnell senior, in only his second year on the PSA Tour, is the wildcard player in the PSA Challenger 10 event celebrating its tenth successive year.
The 24-year-old twice came from behind to topple Koukal, the Czech number one ranked 56 in the world, 8-11, 13-11, 9-11, 11-6, 11-3 in 81 minutes.
Andrew, the world No85 who himself upset Koukal at the same stage in last year's event before going on to make the semi-finals unseeded, took the opening game against Hedrick before the world No60 from Melbourne fought back to win 5-11, 11-8, 11-6, 11-2 in 66 minutes.
"Haven't been this disappointed after a loss in a long time," tweeted Schnell junior later. "Definitely need to reevaluate some things. Happy my bro won though."
Dane Sharp doubled the domestic interest in the last eight round when he beat fellow Canadian Michael McCue 8-11, 13-11, 11-4, 11-13, 11-9 in a 93-minute marathon.
The 28-year-old from Toronto goes on to face Leo Au, the top seed from Hong Kong who received a bye in the first round.
 Leo Au (HKG) bye
Dane Sharp (CAN) bt Michael McCue (CAN) 8-11, 13-11, 11-4, 11-13, 11-9 (93m)
Alfredo Avila (MEX) bt Farhan Zaman (PAK) 11-8, 9-11, 11-4, 12-14, 11-8 (55m)
 Matthew Karwalski (AUS) bt David Letourneau (CAN) 11-6, 11-5, 11-8 (30m)
Graeme Schnell (CAN) bt  Jan Koukal (CZE) 8-11, 13-11, 9-11, 11-6, 11-3 (81m)
Raphael Kandra (GER) bt Yann Perrin (FRA) 12-10, 11-5, 11-4 (30m)
Rex Hedrick (AUS) bt Andrew Schnell (CAN) 5-11, 11-8, 11-6, 11-2 (66m)
 Joe Lee (ENG) bt Charles Sharpes (ENG) 11-7, 11-8, 11-9 (60m)