Completely exhausted after nearly three hours on court, he could barely hold his racket when he served for the match against England's Adrian Waller in the final of the recent National Capital Open in Washington.
Delierre's leg was cramping. His wrist was curling inwards. He was hurting and it was obvious.
Up 13-12, Delierre was convinced he could muster the strength for one final rally. When Waller hit a slightly loose return at the front, the Canadian took advantage to score the winning point to complete an 11-13, 12-10, 14-12, 4-11, 14-12 victory in a whopping 157 minutes.
"It was the toughest match of my life," Delierre said this week during a stopover in Toronto. "I've never seen four tiebreakers in a match."
Waller was up 7-5 and then lost three points in a row, two of them via unforced errors. Delierre moved ahead to 10-8 but the fourth seed saved two match balls to pull even.
They exchanged points until Delierre ended it by putting the ball along the crack where the wall meets the floor.
"I hit this gorgeous drop shot right in the nick — like, unbelievable — and it went my way," he said. "He couldn't pick that one up."
The unseeded 30-year-old from Montreal shook Waller's hand, walked off the court and fell to the ground as the cramping in his right leg was too much to bear.
"My muscles had never gone that far," Delierre said.
According to the Professional Squash Association, it was the longest recorded pro match since a 166-minute battle in 1983 between Pakistan's Jahangir Khan and Egypt's Gamal Awad in England. Khan recorded a 9-10, 9-5, 9-7, 9-2 victory in the Chichester Festival final in an era when the hand-in, hand-out scoring style was used.
The PSA went to the 11-point PAR (point-a-rally) system in 2004, which brought in a more entertaining brand of squash as players were forced to be more aggressive.
Matches now usually last between 20 and 90 minutes. A 157-minute battle takes things to a completely different level.
"I didn't know until I walked off court," Delierre said. "And then I was like, 'Oh, look at the clock.' That's unreal."
Delierre also held the previous record for the longest match in the 11-point PAR era, when he beat Toronto's Shahier Razik in a 150-minute semifinal at the Baltimore Cup in 2008.
Their paths crossed again in Washington. Delierre, who was coming off a long two-hour quarter-final victory, beat Razik in a 60-minute semifinal to advance to the championship.
The final at the US$15,000 Challenger tournament was a contrast of styles. Waller is about six inches taller than Delierre and the two players had several rallies stifled by let calls when they got in each other's way.
They also played on a court with a 19-inch tin, two inches higher than the usual height on tour. With the ball staying up longer, the rallies were extended and it was tough to put the opponent away.
The slim Delierre is known for his fitness and loves to keep the ball in play and grind out victories. Waller was also game and they treated spectators at the Chevy Chase Athletic Club to a classic.
Normally after a long match, players will cool down with stretching or some light cardio work before hitting the locker-room for a shower, sauna and maybe a sitdown in the whirlpool.
No such luck for Delierre.
He drank some water and energy drinks and was hoping to loosen his leg muscles with a ride on the exercise bike. However, the evening match had gone late and the facility was set to close for the night.
"It was a rush to leave," he said. "If it was nice and early I would have taken an hour and really taken out the kinks and screws."
Instead, Delierre hopped into a car and went back to his billet's residence.
"It was impossible to put down food after either ... you can't even enjoy a beer," he said. "I had like half a beer and that was OK. That's what a marathon does to people."
Eventually he was finally able to take a hot shower and soothe his aching muscles.
"The shower was the best," Delierre said. "The shower was the bomb."
He tried to get some rest but couldn't fall asleep until 4 a.m., with his heart rate still high and mind scattered.
"It's just like you're disconnected from yourself, so it wasn't fun," he said with a laugh.
The win gave Delierre his 12th career PSA tournament victory. After a couple days of well-earned rest, Delierre is in New York for this week's qualifier at the J.P. Morgan Tournament of Champions in Grand Central Station.