Jorge Maravilla was not in such a hurry to win the San Francisco Marathon on Sunday morning that he didn’t have time to come to a dead stop a few steps before the finish line.

The Mill Valley resident reached into the spectator section, picked up his 3-year-old son, Joaquin, and carried him across the line with him.

“Give me a kiss,” he said to his son, who dutifully complied.

Maravilla got another kind of marathoner’s welcome, too — a plastic blanket, an energy bar and a banana. Unlike most of the other 27,500 runners, he didn’t need any of them. He appeared to be neither sweating nor panting.

“I feel good,” he said. “The No. 1 goal of a marathon is to have fun.”

Finishing 12 seconds behind Maravilla was Jonathan Briskman, who had been ready to take advantage if Maravilla’s playful decision to pick up his son had ended up taking too long. It didn’t. Crossing the line 26 minutes behind Maravilla was the first woman, Bonnie Tran.

Now Playing:

Maravilla, 40, a former farmworker from El Salvador, seemed to be enjoying himself for the entire two hours, 27 minutes and 56 seconds it took him to navigate the course. In the Richmond District, around the halfway mark, he joyfully leaped over a parked San Francisco police motorcycle.

At the finish line, Joaquin whispered a question into his father’s ear.

“Why did I do it?” Maravilla replied with a smile. “Because it was there. I had to jump over it.”

The winner’s wife, Ashley, was there, too.

“Not bad for a 40-year-old guy,” she said.

These days, marathon running is such a big business that when Maravilla noticed that the energy bar he had been handed by a race volunteer was not the same brand of energy bar as the one that sponsors him, his face finally lost a bit of color — something it had not done for the previous 26.2 miles through the streets, parks and byways of San Francisco.

“Uh-oh,” he said, and he tossed the interloping energy bar aside.

At 5:30 a.m., the runners set off from the Ferry Building along the Embarcadero, through Fisherman’s Wharf, across the Golden Gate Bridge and back, and then, via the Presidio, the Richmond District, Golden Gate Park, the Haight, the Mission District and Dogpatch, back to the Ferry Building.

Runners wear an electronic timing chip on their shoelaces that registers the precise second they cross the starting line, to keep things fair. By the time the last marathoner had officially started, Maravilla was more than a mile down the road.

This year, to avoid bridge congestion, runners were permitted only on the sidewalk, not the roadway. And only full marathoners, not half-marathoners, got to run on the bridge. The route changes caused a minor kerfuffle in the marathon world and organizers felt obliged to offer refunds to complainers.

But the race went off without incident, as most well-organized things that happen at sunrise do. All but forgotten was the 2015 finish line mix-up that saw a confused Maravilla diverted onto the wrong path and ending up in third place.

At this year’s finish line were the usual: a line of massage tables, three medics with wheelchairs, a long line of cheery blue outhouses and a bunch of doctors ready to intravenously administer pick-me-up sugar water. There were also either 16,000 bananas, 25,000 bananas or 80,000 bananas — the person in charge of the bananas wasn’t sure.

“A lot of people take extra bananas,” said banana supervisor John Ross, who added that runners who pay the $269 entry fee are “entitled to take as many bananas as they need.”

It was a typical marathon morning. Moments after the starting gun, the clothing scavengers were out and about. Marathoners traditionally shed extra layers of clothes just before the starting gun, tossing them on the sidewalk at the starting line for needy folks to help themselves.

“I don’t have enough clothes, and these are just going to waste,” said Robby Steinmiller, a part-time security guard from San Francisco who picked out a half-dozen shirts from big piles. With several hundred garments to choose from, he could afford to be selective.

“I’m looking for North Face,” he said. “I don’t like the fuzzy, cheap stuff.”

As always, hundreds of volunteers made sure the race ran smoothly. One volunteer, San Francisco medical student Matthew Crimp, manned one of the wheelchairs, ready to haul off overwhelmed runners to the medical tent. There were several customers, and Crimp also found time to sprinkle a bag of kitty litter onto a spot in the middle of the Embarcadero, after one runner’s energy bars decided to make a premature exit.

“It’s part of the job,” Crimp said.

Competitive running is for everyone, which is why there was a 5-kilometer race, too. Those competitors set off on their short jaunt only moments before the marathoners finished their long ones.

One of the 5K runners, professional dog walker Sean Gattis of Walnut Creek, said walking dogs is the perfect way to train for a race.

“It keeps you in shape,” he said. “I’d like to thank all my dogs, especially Riley, Ella and Dexter. They all helped get me ready for today.”

Steve Rubenstein is a San Francisco Chronicle staff writer. Email: srubenstein@sfchronicle.com Twitter: @SteveRubeSF