The vehicles collided in the eastbound lanes near exit 36 in North Hills at around 12:45 a.m.
Both drivers were extricated from their vehicles with injuries described as minor.
But the crash shut down both sides of the expressway for hours, as authorities determined what to do with the overturned tanker.
The tanker was transporting liquefied petroleum gas (LPG), which is highly flammable.
Out of an abundance of caution, officials closed all eastbound lanes at exit 36, and all westbound lanes at exit 37.
The eastbound service road was also closed as authorities dealt with the delicate task of safely uprighting that tanker and moving it out of the way.
The closures created a traffic nightmare for commuters that lasted through much of the morning rush hour.
The tanker was finally uprighted shortly before 6 a.m. and the westbound lanes were reopened.
The eastbound lanes remained closed as cleanup work continued. All but one of those lanes were back open by 7:30 a.m.
All lanes were finally back open, and traffic flowing normally again, by 9 a.m.
Accident investigators were working to determine exactly what led to the crash.
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