SAN FRANCISCO -- Sometimes on Sunday, it looked like Anquan Boldin and Colin Kaepernick were playing a private game on their own, only occasionally allowing others to join in.
Boldin ran down field, Kaepernick kept throwing it to him and Boldin made the play, whether there were Packers defenders nearby or not.
Their game, their connection: They combined for 13 completions for 208 yards in the 49ers' 34-28 victory at Candlestick Park to open the season, and they made it look inevitable.
Nobody else could intrude -- Kaepernick was too accurate and too mobile, and Boldin was just too strong.
It was their own private football island out there. Nobody could do anything about it.
And, given Kaepernick's skill and Boldin's determination, I'm not sure anybody is ever going to be able to.
"They kept letting him get open," Kaepernick said with a smile about his day with Boldin.
"And he played like a grown man today. He made plays even when he shouldn't have. So if he plays like that, he's going to get the ball even more."
Of course, Boldin is no speedster. Defenders can and will stay with him.
But if the QB is ready to keep throwing it to No. 81, who's going to stop Boldin?
On Sunday, Kaepernick threw to Boldin when he was left wide open, which happened more than a few times Sunday.
Kaepernick threw to him when he was partially covered -- and Boldin just outfought the Packers for the ball.
And on a critical fourth-down play, late in the game, Kaepernick (who threw for a career-high 412 yards) just drifted right and waited and waited for Boldin to get a tiny bit open, then fired it to him for a game-sealing 15-yard gain.
What was Boldin thinking while Kaepernick was searching for him on that play?
"Just stay alive," Boldin said. "Whenever you have a quarterback like Kap, he can get outside the pocket and make plays happen.
"You have to stay alive with him."
Overall, Kaepernick targeted Boldin 17 times in their first game together, with one TD hookup in the second quarter and a long gain of 43 yards that set up the Frank Gore touchdown that put the 49ers ahead for good.
Not a terrible 49ers debut for Boldin, who had six key catches for 106 yards and a touchdown against them in the Super Bowl and then came west when the Baltimore Ravens decided they couldn't afford his $6 million salary this season.
"Man, he's a monster," said 49ers cornerback Tarell Brown.
The 49ers got Boldin for only a sixth-round draft pick, by the way, back in March with the thought of making him a nice complement for No. 1 receiver Michael Crabtree.
Then Crabtree blew out his Achilles a couple months later, and Boldin became the 49ers' only proven receiver to start the 2013 campaign.
And now he's carrying a 13-catch performance into the huge Week 2 game against ultra-rival Seattle.
So how brilliant was the trade to get Boldin?
"We did give up a draft choice for him and (are) paying him a lot of money," coach Jim Harbaugh said of Boldin. "But definitely think he's worth every penny."
Then Harbaugh just started laughing, which he does not normally do in postgame moments with the media.
"I think he's worth ev-ery penny."
Said Kaepernick, with a bit of a wry smile: "Yeah, I think we got the better end of that deal."
The funny thing about Boldin is that he looms so large on the field, but up close and in real life, he doesn't look nearly as imposing.
He's listed at 6-foot-1, about 220 pounds, but looks smaller. He's quiet.
And when the cameras come around and people expect showy demonstrations, Boldin's almost always looking for some place to hide.
On Sunday, he bolted off the field directly into the 49ers locker room seconds before the final gun, leaving behind a 49ers P.R. person tasked to keep him around for an on-field interview.
No TV interview, no Boldin. He was gone.
"That's just how I am," Boldin said later at the podium. "For me, it's a business. I come out here to do my job."
So, is this just a one-game anomaly?
In 19 games with Baltimore last season -- including three in the postseason -- Boldin had only three 100-yard receiving games, and two of those came in the playoffs.
But judging by the way he and Kaepernick have connected almost from the first day Boldin arrived in camp, it seems like his 49ers career is destined for much larger performances.
It's the right QB throwing to the right receiver, and just look at those two guys: Really, who's going to stop them?
49ers (1-0) at Seattle (1-0),
5:30 p.m. NBC