If Minato can summon Gamabunta and have him blast Sasori before he can do anything, he should win, since Sasori's actual movement speed isn't that great and Gamabunta's attacks cover a lot of area.
So Minato may have a huge speed advantage, but I don't see the gap being so large that Sasori is incapable of reacting to it. Sasori was also quick enough to evade being broken into pieces when Sakura broke Hiruko. In fact, it appears as though he dodged while Sakura's fist was penetrating Hiruko's shield. Assuming Minato's Rasengan breaks through Hiruko (which I'm sure it probably can), Sasori will have ample time to escape, especially considering that Minato is not aware that Hiruko isn't Sasori himself.
When the Kazekage puppet is withdrawn, things become a little more difficult. Minato's special kunai are now not only almost useless (I say almost), but can actually be used against him. This is what I'm getting at with Creativity & Intelligence Feats. Sasori is not an idiot, and he's able to decipher how things work and how certain things are accomplished relatively easily. In virtually the same instant it happened, Sasori figured out that Chiyo had attached chakra strings to Hiruko's tail, despite the threads themselves being suppressed to a level that they couldn't be conventionally detected. He was able to completely counter every single move Kankuro used against him in their initial fight. This can't be wholly attributed to knowing about all the puppets' traps, because part of puppetry (especially in Kankuro's case) is setting up combinations between traps that lead to an effect that's greater than the parts, and utilizing those same traps in different ways to accomplish different results.
It doesn't take a rocket scientist to figure out how Minato's Hiraishin works, and Sasori will likely figure it out on the first usage (C'mon, it's an extremely elaborate kunai that looks nothing like anything else.. and Minato automatically appears next to it). So even if he didn't have Hiraishin knowledge it wouldn't make a huge difference. Sasori, with the magnetic force generated by the Sandaime puppet, could easily move the kunai around as he desired.
Minato does have the ability to place these seals on his own, with no metal involved. This is advantageous, but also carries a disadvantage that could be extremely detrimental against a cunning ninja, or one that relies on cunning nearly entirely such as a puppetmaster. The seals don't move. The Kunai can be thrown, but a seal placed on the ground isn't going anywhere. Once Sasori figures that out, he'll note the locations that have been marked (or at least the ones he can perceive).
After this, it becomes a simple matter of manipulating the kunai. Knowing where the stationary seals are located and being able to control the metallic kunai assures that, at all times, Sasori will know where Minato can teleport and where he can't. Given the huge amount of Iron Sand available and the lethality & range of Sasori's Satetsu attacks, he's very capable of attacking most if not all of these points simultaneously, and the axiom we all know comes in ''One Scratch Is All It Takes''.
Then there's chakra strings themselves. Kankuro, in his first appearance, demonstrated the ability to physically affect things with chakra strings even if they weren't directly connected to the object or person in question. He did this by tripping Naruto. Sasori demonstrated the ability to control a living being against their will, even though they were weakened at the time. Sasori can create at least (presumably), 110 strings simultaneously, using them to control any loose object in his surroundings, as well as attempt to physically ''assault'' Minato with them.
Sasori, then, still has his true body and 100 puppets. The 100 puppets probably won't be too much of an issue, since it appears as though Sasori doesn't put much care for control in their usage so much as use a ''brute force'' tactic. This still will put incredible pressure on Minato, and in addition to Sasori's normal (exiting Hiruko) dodging capability, he has his stinger-cable thing to help his evade and move in unconventional ways. He also has flamethrowers, and we all know burning stuff is fun.
Minato uses his space-time barrier on Satetsu Kaiho and one-shots Sasori with his own technique
