United States GP: Pierluigi Martini, Minardi M189 Ford, leads Nelson Piquet, Benetton B189B Ford, and Thierry Boutsen, Williams FW13B Renault.
Pierluigi Martini, Minardi M189 Ford, leads Nelson Piquet, Benetton B189B Ford, and Thierry Boutsen, Williams FW13B Renault.