The Sharks got timely saves from Martin Jones - though he did not have to perform many heroics - including a crucial one midway through the second period on Jori Lehtera with the left pad.
That was when the Blues made their first push. Their next one came too late in the third period with Vladamir Tarasenko's first two goals of the series.
The Blues didn't have enough to overcome the Sharks.
"They looked a little bit worn down," Agnew said. "But I think San Jose played pretty much a complete game. Other than that five-minute period in the second period where St. Louis threatened and the Tarasenko deal at the end, for the most part [San Jose] wanted nothing to do with going back for a Game 7.
"They knew they had a chance to end the series and I think San Jose played that way. They skated, they checked hard. They competed in those one-on-one battles. Like, the puck's up for grabs, the team that's the second man in there can get the puck and usually has the advantage, and I thought both offensively and defensively, San Jose was quicker to pucks with their second man."
He added, "I also thought that San Jose, especially early on, chipped pucks deep on the same side, so as they were attacking that defenseman on the one-on-one they weren't rimming it, they weren't cross-ice dumping it. Everything was on the same side, chip into the corner, and making the defenseman turn and go get it. I thought that played a part in sort of wearing some of [the Blues'] top defensemen down."