ST. LOUIS -- Some things just seem to be agonizing. For the St. Louis Blues, the inability to finish scoring opportunities have them down 3-2 in the Western Conference First Round series against the Chicago Blackhawks.

The Blues' 3-2 overtime loss to Chicago in Game 5 on Friday saw the home team lose for the first time in this series. Just as in 2013, when the Blues jumped to a 2-0 series lead against the Los Angeles Kings in the Western Conference Quarterfinals before losing in six games, they are on the brink of elimination as they head to Chicago for a must-win Game 6 (3 p.m. ET; NBC, CBC, RDS).

And much like 2013, the inability to bury their scoring chances is exacting a huge price. They led 2-0 in this series and now have dropped three straight.

"Yeah, again, I think same story we had plenty of chances to take bigger leads," forward Alexander Steen said. "We didn't. Cost us on the power play again in the first period. We had a couple we didn't convert on.

"You want to win in the playoffs, you've got to score on your chances."

When scoring chances are there against the defending Stanley Cup champions, teams have to take advantage of them. The Blues have had their fair share of opportunities in the past three games -- and lost all three.

The Blues were buzzing after getting the tying goal from T.J. Oshie in the second period and appeared poised to take the lead. But a pair of golden opportunities went awry. Vladimir Sobotka took a terrific pass from Vladimir Tarasenko pass that left him wide open in the right circle, but fired high and wide. Oshie also pounced on a turnover in the slot and fired high, another open opportunity.

The Blues had another 3-on-1 rush in the third period. Jaden Schwartz saucered a pass to Oshie, who initially had trouble corralling the puck, but Chicago goaltender Corey Crawford got the paddle of his stick on the shot.

That's how things went for the Blues offensively.

"We were really going in the second, had those odd-man rushes in the third," Blues coach Ken Hitchcock said. "Made four or five mistakes and paid for it three times."

"We had some opportunities, open nets, that we should have hit. At the end, they get a breakaway and they get the winner."

Adam Cracknell's wrister from the left circle in overtime also went wide of Crawford. The Blues had their moments in this game, but in the end, Chicago captain Jonathan Toews came up with the big goal.

The Blackhawks and Blues played their fourth overtime game in the first five contests of their First Round series. According to the Elias Sports Bureau, it marks the fifth time in Stanley Cup Playoffs history that at least four of the first five games of a series have required overtime. The Blackhawks were also involved in the most recent one; they went to OT in each of the first five games in their opening-round series against the Phoenix Coyotes two years ago.

Overall, the Blackhawks-Blues series marks the 13th time in the history of the Stanley Cup Playoffs that a series has required at least four overtime games. And in a series where there is such a fine line, the difference between finishing and missed opportunities is magnified.

"It seems against a team that's got this type of finish, you make a big error, you pay for it," Hitchcock said. "That's what's happened in this series. We've played extreme hard, at times dominated, played to our potential, played with structure, but when we make an error like on the first goal, on the third goal we paid for it. That's what's happened.

"We're paying for our mistakes and they got people who know how to finish and making us pay for it."