Manages to outgun Rainey and hold off Doohan and Daryl Beattie to slot in behind the Team Lucky Strike Suzuki riders in third.
Exiting the Anti-Banked Curve (Turn 6), a group of three starts to form, consisting of Schwantz, Barros and Ito.
Ito then loses out a bit entering Degner (Turn 8), immediately being hounded by fellow Japanese Fujiwara.
Barros has by now overtaken Schwantz for the lead, with the American trying a lunge up his inside coming up to the Casio Triangle (Turn 15), not being able to execute the move and having to stay behind for the time being.
Crivillé passes Fujiwara for fourth at the start/finish straight entering the First Corner, Rainey doing likewise on Honma for seventh position.
At the Backstretch, Schwantz looks to be taking the lead from Barros but instead it is Ito who has taken first place from both riders, making good use of his superior Honda power to blast past before approaching the fast 130R (Turn 14).
Exiting Dunlop, it is clear that Barros is now starting to struggle, losing ground to teammate Schwantz and with Crivillé and Rainey catching up to him quickly.
Schwantz is now very close to Ito, making his move and passing him for the lead at Spoon Curve (Turn 13), going up his inside and outbraking him as a result.
Schwantz tries to outbrake Ito entering the Casio Triangle but the Japanese has opened up enough of a gap to stay ahead for now.
Entering Spoon Curve, Schwantz catches up a bit to Ito as Barros has now opened up a significant gap back to Rainey, who has passed Crivillé and is now fourth.
On lap six, Schwantz has opened up a big gap to his teammate Barros, who himself is now coming under pressure of both Rainey and Beattie.
Rainey has by now fully caught up to Barros and almost directly makes a move, going up his inside at Snake (Turn 5) and pushing the Brazilian slightly wide to get the perfect line exiting the corner.
At Snake, he dives down his inside and takes away second position from him, then immediately opening up a small gap in pursuit of Ito.
He tries a move at the second part of the corner but just falls short, allowing Ito some breathing room coming onto the Backstretch.
At the Casio Triangle on the previous lap, John Reynolds has crashed out, losing the front entering the chicane and beaching his bike in the gravel at low speed.
However, Ito blasts past Rainey and retakes first place, making good use of his superior Honda power.
At said corner, he goes around the outside, making good use of the superior corning of the Yamaha to go past Ito and take the lead, almost going on the grass in the process.
Exiting Spoon Curve, Ito has a slight moment which allows Rainey and Doohan to stay close behind the Japanese.
At the end of the Backstretch and entering 130R, Schwantz then makes a move and goes up the inside of Rainey, taking second position away from him.
On lap twelve, Ito blasts past Schwantz' Suzuki to retake the lead entering the First Corner.
Ito then effortlessly repasses Schwantz at the Backstretch, with Beattie catching up and passing Rainey for third right before the 130R as well, making this a full-on four-way battle for the win.
At the entrance of Spoon Curve, Beattie passes Ito around the outside, going a bit wide but retaining second place.
At the Anti-Banked Curve, Schwantz throws his bike up the inside via a tight line, passing Beattie and taking over at the front.
Exiting Turn 10 and entering the Hairpin, Rainey makes his move and dives down the inside of Beattie, overtaking him for second position.
At Dunlop, Rainey takes a slightly wider line but is able to get side-by-side with Schwantz, opting to stay behind for the time being.
At the Backstretch, Rainey overtakes Schwantz for what he thinks will be the lead, but instead it is Beattie who shoots past both riders to snatch first place away from them upon entry of the 130R.
At the fast Turn 10, Schwantz dives down the inside as the Japanese blocks him, the American still finding a way past as they enter the Hairpin and Ito goes wide.
The group has to overtake three backmarkers - Alan Scott, Bruno Bonhuil and José Kuhn - they manage to get past of except for Schwantz, who gets blocked at the entrance of the Casio Triangle.
Both Rainey and Schwantz wave at the crowd, then stopping at the Snake complex as a fan who invaded the track hands him the American flag.
The podium girls hand the riders the champagne, Schwantz then cheekily running after Kenny Roberts and spraying him in the commentary booth as a result.