In New England's 2-1 triumph over Sporting Kansas City, the 38-year-old first came up with a critical save on Teal Bunbury in the 34th minute, then provided another on Dominic Dwyer in second-half stoppage time.
Largely thanks to Reis, who boasted a 7-1-4 regular-season record, the Revolution emerged from the Eastern Conference semifinal first leg with the one-goal advantage.
"His reflexes are pretty amazing," New England coach Jay Heaps said. "I don't think there's been a better goalie in the league that has reflexes like that."
While seeing just 39.6 percent of the possession, New England took advantage of miscues and finished the few chances it created. The second goal by Rowe came on the counterattack, when Kansas City was pressing high in search of an equalizer.
"Nobody wants to make a mistake so you need that little bit of a break. You need that little bit of luck. I thought we did a great job on both goals," Reis said. "Credit to our guys that put the work in on both sides of the ball. Defensively, we played a great game and offensively we got two goals."
Kansas City, however, grabbed a critical set-piece goal from defender Aurelien Collin in the 69th minute that gave Sporting a lifeline going into the second leg Wednesday.
"It's a big goal for us to lessen the gap," said Kansas City coach Peter Vermes. "You don't always necessarily know if you're always going to win when you go away from home, but to keep the score line the way we did is great."
New England was certainly frustrated with the late goal, but the performance at home got the team off to the right start in its first playoff appearance since 2009.
"We needed to step our game up and fortunately we got two tonight," Heaps said. "It would have been nicer to have a two-goal advantage, but credit them for a great goal and a great finish on their end."
In addition to boasting roughly two-thirds of the possession, Sporting also fared well on set pieces, something Heaps said he expected going into the game. Looking ahead to Wednesday night, Kansas City will look to again dominate the possession as a way of limiting time on the ball for potent New England attackers Diego Fagundez and Juan Agudelo.
But capitalizing on its few opportunities has kept hope alive for New England. Despite only being up one goal, the team is confident.
"In this series, it's like we're at halftime. So we are up 2-1 at halftime," Reis said. "The more pressure we can put on them, it's great for us. It's going to be a tough task going in there and getting a result, but I like our chances."
The emphasis on home-field advantage can never be underestimated in the MLS playoffs. If Sporting can control the tempo of play once again, their home crowd could be the final advantage needed to overtake the Revolution.
"I thought we were pretty unfortunate to come away with a loss in this game," said Kansas City left back Seth Sinovic. "But like I said, one goal is not an insurmountable task. We've got an unbelievable fan base to come home to."