The Stampeders quarterback threw for 124 yards and a touchdown on Thursday night to improve to 7-0 as a CFL starter and help Calgary edge the Edmonton Eskimos 26-22.
Rene Paredes nailed four field goals as the Stampeders improved to 4-0 on the season. Mitchell, meanwhile, tied former Stampeder Jeff Garcia's league record for best career start.
But after the game, Mitchell downplayed the accomplishment.
"It's not a record that people even keep track of, I'm surprised people even keep it," he said. "I'm excited to be undefeated, but I'm more excited our team is playing well and that we are undefeated. I'll try to keep that record intact as long as I can, but a loss is going to come at some point."
Edmonton was guilty of a couple of major gaffes in the game, including the questionable decision to try and run a fake punt out of the end zone late in the second quarter, a failed effort which led directly to a costly Calgary touchdown.
"I was surprised they did that," said Stampeders head coach John Hufnagel. "We were very fortunate to be able to stop that by inches. It was a big play of the game since we scored on the next play. This is the type of game where a head coach has to make decisions to try and help their team win. I went for a third-and-one and was stopped. You have to take those chances and just hope that they are executed.
"We're struggling offensively, but we are still winning. We need to get better and hopefully we will get better."
The Eskimos dropped to 4-1 on the year, missing out on a chance to surpass the total number of wins they had in a disappointing 4-14 campaign in 2013.
"You'd like to win them all, you'd like to go 18-0 and then win two more in the playoffs," said Eskimos quarterback Mike Reilly, who threw for 212 yards with one TD and one interception. "But the reality is that's not going to happen, so you try to learn from these experiences.
"This is a good football team that we played against. They've got the best record in the league now, but we also learned that if we do a few things better, we could win that football game."
Edmonton's defence was forced to come up big early as Eskimos punt returner Jamal Miles coughed up the ball just over a minute into the game on his own 27-yard line. That was as close as Calgary got, however, as they were held to a 36-yard Paredes field goal.
The Eskimos came right back on their next possession with a 31-yard Grant Shaw field goal to tie it 3-3.
Calgary came up with another big special teams play with six minutes remaining in the first quarter as Keenan MacDougall blocked a Shaw punt deep in the Edmonton zone and was able to pick it up and ramble the remaining six yards into the end zone to put the Stampeders up 10-3.
"I kind of went through untouched," MacDougall said. "I had a nice bounce into my hands after a couple of other bounces."
Pat White replaced Mike Reilly at quarterback to start the second quarter and instantly drew a pass interference call on an end zone pass. He would then take it in from the one-yard line to knot the game back up. It was White's first CFL touchdown.
Edmonton looked to have surged in front two minutes later on a 59-yard passing play from Reilly to Fred Stamps, however the play was called back on a holding infraction.
The defensive battle continued as Fred Bennett picked off a Reilly pass at the Edmonton 45, eventually leading to a 36-yard Paredes field goal.
The Eskimos responded with a 40-yarder from Shaw.
Edmonton tried a fake punt with 24 seconds remaining as defensive back Aaron Grymes took off with the ball from his own end zone. It was a costly risk, however, as he was stopped just short of the first down, leading to a 16-yard touchdown pass from Mitchell to Jeff Fuller and a 20-13 Calgary lead at the half.
The Eskimos atoned for the miscue six-and-a-half minutes into the third quarter as they stopped the Stamps on a third down gamble at the Calgary 32-yard line. The next play Reilly was able to pass to a wide-open Shamawd Chambers for the touchdown to tie it once again.
Calgary regained the lead in the pouring rain with just over a minute remaining in the third frame on a 29-yard Paredes field goal and then benefited from a bevy of Edmonton penalties to make it 26-20 six minutes into the fourth quarter on a 30-yarder from their kicker.
Edmonton had a chance for an easy first down with one-and-a-half minutes down, but instead of driving it the inches necessary, tried a passing play only to see Reilly get sacked to force a punt.
Calgary gave up a safety with 44 seconds left to run some time off the clock and put Edmonton on their own 35. The move allowed the Stamps to run out the clock from there.
The Stampeders return home to face the B.C. Lions next Friday. Edmonton has a bye week before starting a two-game road swing in Montreal on Aug. 8.
Notes: The last time the Eskimos were able to come away with a win against their provincial rivals was on Sept. 5, 2011. Calgary came into the game with eight wins in a row over Edmonton in the head-to-head match-ups. … The Stampeders were without reigning CFL Most Outstanding Player Jon Cornish, who was placed on the six-game injured list with concussion symptoms. … Eskimos linebacker J.C. Sherritt missed his fourth game this season. … Calgary came into the game having allowed just three sacks this season, while Edmonton's defence led the league with 18. … The Stamps entered the match-up having surrendered a CFL-low 10 points a game, and just one touchdown, compared to the 14.5 scored against the Eskimos. … Fans were just as interested in the 50/50 draw as they were the game. In their last home game against Ottawa, the jackpot of $71,732 went unclaimed and carried over to the game against Calgary. The potential for a big draw ignited a frenzy, as fans endured long lines to get a crack at the pot, which ended up at an astounding and record-setting $348,534. Because of the heavy demand, the draw couldn't be announced at the game. Instead plans were in place to announce it on the team website. ... The attendance for the game was a league season-high 40,066.