On lap 6, the green flag came back out with Mario Andretti on the lead…..while driving at a blistering pace ….as it took only 7 laps for him to start lapping back markers….when on lap 25, Ludwig Heimrath, Jr. was running 7th…..and made his first pit stop…..but one of the wheels on his car was not properly secured…. which led to the wheel coming off…..and he spun in turn four…..so, under the caution….Mario Andretti pitted and managed to stay in the lead…..as only 7 cars remained on the lead lap.
Around the 100-mile (160 km) mark….several cars were dropping out of contention…..when Kevin Cogan blew an engine….Randy Lewis dropped out with a gearbox failure…..and Michael Andretti broke a CV joint….and then had a pit fire….then on lap 34, Bobby Rahal, who had been running as high as 2nd, made an unscheduled five-minute long pit stop due to an electrical problem….to which after several long stops….Rahal would eventually drop out.
Mario Andretti continued to dominate….while giving up the lead temporarily only through the sequence of pit stops….with Roberto Guerrero and Danny Sullivan consistently chasing him…..then shortly before the halfway point….that is when Rick Mears was forced to the pits with an electrical problem….and would also be forced to drop out.
At the 90 lap mark….Al Unser, Sr. had worked his way up to 4th…..with Tom Sneva in 5th…..while Super Mario was still dominating by running laps in the low 200’s mph range….while most other cars were in the 190 mph (310 km/h) range, or slower. Dick Simon was running 7th….but ran his car out of fuel on the backstretch….as he lost several laps when being towed back to the pits….but received fuel and returned to the track. Mario Andretti was leading comfortably as the drivers passed the halfway mark and 120 laps into the race.