United States GP: Ayrton Senna, McLaren MP4-5B Honda, battles with Andrea de Cesaris, Dallara BMS-190 Ford, while Pierluigi Martini, Minardi M189 Ford, leads Nelson Piquet, Benetton B189B Ford, and Thierry Boutsen, Williams FW13B Renault, behind.
Ayrton Senna, McLaren MP4-5B Honda, battles with Andrea de Cesaris, Dallara BMS-190 Ford, while Pierluigi Martini, Minardi M189 Ford, leads Nelson Piquet, Benetton B189B Ford, and Thierry Boutsen, Williams FW13B Renault, behind.