Plymouth boss John Sheridan praised goalkeeper Luke McCormick for ensuring the League Two side's 3-2 Johnstone's Paint Trophy win against Swindon Town.
Lewis Alessandra scored two first-half goals, either side of Deane Smalley's effort, before League One high-flyers Swindon fought back after the break.
McCormick's injury-time save from Ben Gladwin's close-range shot secured Plymouth's passage to the last 16.
"It was incredible," Sheridan told BBC Radio Devon.
"Luke wanted to play. It would be nice to give James Bittner game time, but I think it gives the lads confidence to see what I think is the best goalkeeper in our division behind them."
McCormick, 31, who missed the last four months of the 2013-14 season with a finger injury, has started every match for Plymouth this term.
However, Sheridan opted to make a number of other changes for Tuesday's JPT tie and was pleased with their response against the second-placed League One side.
Plymouth are currently eighth in League Two, two points outside the play-off places, and the Pilgrims manager is hopeful that their run in the competition will influence their league form.
"I thought all the players who came in did a really good job," Sheridan said.
"We have to remember we played a really good team and they are comfortable on the ball.
"This is a competition I want us to win, and this win gives us confidence which I want to take into our league form."