Colorado Avalanche prospect Mason Geertsen had the game-tying goal and an assist in the deciding contest. Julien Nantel had two shots, while Sergei Boikov had one.
The Eagles trailed 3-2 after 40 minutes of regulation, but Geertsen tied the game at 3-3 just 35 seconds into the third period. Matt Register scored the game-winner with 1:09 left to play.
Goaltender Kent Simpson made 23 saves in the win.
Colorado didn't have much time to get ready for the first game of the conference finals on Friday, as the Walleye was waiting for the squad in Ohio after wrapping up its five-game series against the Fort Wayne Komets three days before the Eagles.
Despite the quick three-day turnaround, the Eagles were first to get on the scoreboard, tallying at 18:40 of the first period. The lead was short-lived as Toledo scored with 20 seconds left in the frame and added two more in the first 1:23 of the middle stanza.
Alex Belzile cut the deficit to 3-2 with 2:28 left in the second, but the Walleye sealed the win with an empty-net marker in the final minute of the third period.
Defensemen Boikov and Geertsen both finished with two shots, with Geertsen also getting two penalty minutes for slashing. Nantel had one shot and a plus-1 rating.
Colorado had a much better second game on Saturday, as the team scored three first-period goals and held on for a 4-3 victory.
The outing had the opposite start to the one the night before, as it was the Walleye that scored first before the Eagles railed off three straight. Nantel assisted on Jake Marto's tying goal at 5:37 before picking up his fifth marker of the playoffs 2:18 later. Belzile then scored at 8:50 to stretch the lead to 3-1.
Toledo tallied midway through the second and third periods, but Register's goal 1:44 into the third period proved to be the game-winner.
Nantel is fourth on the Eagles with eight points and third in goals with five after 13 games played. Geertsen is third on the team with 27 penalty minutes, while having also contributed a goal and three helpers in 12 contests. Boikov has three assists and six penalty minutes in 11 postseason outings.
The Eagles will host the next three contests of the series at the Budweiser Event Center in Loveland, with Game 3 set for Wednesday. Game 4 is Friday and Game 5 is Saturday.
Upcoming Schedule:
Game 3 - Wednesday, May 17 vs. Toledo Walleye
Game 4 - Friday, May 19 vs. Toledo Walleye
Game 5 - Saturday, May 20 vs. vs. Toledo Walleye
Game 6 - Monday, May 22 at Toledo Walleye, if necessary