SAN FRANCISCO -- Oracle Park’s decibel level likely reached its highest point of the season. Orange rally rags made a regular-season appearance. And, as has been the case all year with these Giants-Dodgers games, drama saturated the night.

Friday night’s heavyweight bout between San Francisco and Los Angeles, the first of three this weekend, had a playoff atmosphere that lived up to the billing.

On a night filled with too many substitutions to count and equal amounts of blunders and spectacles, the Giants won, 3-2, on, bizarrely enough, an 11th inning, bases-loaded walk-off throwing error beaten out by known speedster Buster Posey after Will Smith, making his first career appearance at first base, couldn't keep his toe on the bag. Given how the night unfolded, it was an appropriate end to a odd marathon.

• Box score

“It’s up there at the top, for sure,” Posey said of where this game ranks in his experience in the rivalry.

San Francisco entered the ninth inning in position to begin the series with a win. Anthony DeSclafani had been masterful and the bullpen had been nails. Manager Gabe Kapler’s aggressive third-inning substitution of Austin Slater for LaMonte Wade Jr. netted the Giants their lone run of the ballgame to that point. But as has been the case with clashes between West Coast titans, endings are seldom clear-cut.

With one out in the ninth, Justin Turner singled and Corey Seager doubled off closer Jake McGee, putting the tying and go-ahead runners in scoring position. The Giants brought the infield in. Smith hit a sharp liner at Thairo Estrada and Turner made an ill-advised break for home. Seager and Turner both ended up on third, and Seager was out by way of being the trailing runner. Turner actually wandered off the base after Seager was ruled out, but Posey went to tag Seager, and Turner got back to the bag just in time.

Turner’s baserunning blunder only set the stage for Chris Taylor, who muscled a bloop single into center field to tie the game up at one run apiece. The Giants couldn’t score in the bottom of the frame despite putting a runner in scoring position, and it was on to extra innings.

The Dodgers managed to cash in their automatic runner in the top of the 10th inning, but this time, the Giants had an answer in the bottom half. Brandon Crawford, who had been stranded after his leadoff double in the eighth, singled home Posey, the Giants’ automatic runner, to tie the game at two.

"I felt like I hit it just slow enough to be able to score him and hard enough to be able to get through," said Crawford. "It was just really good bat control, I think, by me there."

But, alas, Crawford was again stranded, this time at third. So, another inning.

The Dodgers had their own golden opportunity in the 11th, putting runners at the corners with no outs following a Seager single, but Turner had another gaffe on the bases. With the Giants’ infield playing back, Smith, again, hit a sharp grounder, this time at Crawford. Instead of going for two, Crawford fired home to nail Turner. That effectively ended the Dodgers’ rally and paved the way for Posey’s mad dash.

“There was no thought of going two when I saw how the ball was hit,” Crawford said.

With the bases loaded in the 11th and two outs, Posey hit into what looked to be an inning-ending groundout. A good throw would’ve sent the game to the 12th, but second baseman Trea Turner threw it wide to Smith, who had his toe come off the bag, allowing Posey to make it safely. The Dodgers immediately challenged the play. Following a very lengthy replay review, the call stood.

“When he needs to move, he can move,” Crawford said. “I wouldn’t call him fast by any means, but when he needs to move, he can run. I think he was as ready as anybody for that game to be over and go home.”

By the time the call came in, the Giants had all returned to the dugout. Kapler described the celebration as equal parts joy and relief. The home crowd erupted even when no one but the umpires were left on the field, almost looking as if they were cheering ghosts.

“I don’t think we’ve ever had a walk-off win celebration in the dugout, so that was a first,” Posey said.