John Holden and Andrew Winkle secured their second sidecar TT win - in a race marred by the death of fellow competitor Dwight Beare.
The Lancastrian pair took a dramatic victory by almost a minute from Peter Founds and Jevan Walmsley, with Alan Founds and Aki Aalto third.
Ben and Tom Birchall had led Saturday's race by 34 seconds before retiring on the third and final lap.
Sidecar driver died after crashing near Rhencullen.
His passenger, Benjamin Binns, was airlifted to the island's Noble's Hospital with a fractured ankle.
The race was re-flagged and restarted following the incident.
The Birchall brothers set a new outright lap record of 116.798mph on their second lap as they built a commanding lead before stopping Sulby Crossroads on the final circuit.
Seventeen-time winner Dave Molyneux and passenger Dan Sayle did not start the race after a problematical qualifying week.
Holden and Winkle's second TT win came five years after their first, in 2011, and both Petere and Alan Founds secured their maiden TT podiums with Jevan Walmsley and Aki Aalto in their respective chairs.