Andy Irons has four Triple Crown championships in the past five years.

Irons' lead in the overall Triple Crown standings became insurmountable when Australia's Taj Burrow was eliminated in Thursday's third round of the Rip Curl Pro Pipeline Masters. Burrow, who was the only surfer with a mathematical shot at catching Irons, placed fourth in the second heat of the third round.

Irons, who now has four Triple Crown championships in the past five years, is scheduled to surf today in the seventh heat of the third round.

The final day of the Pipeline Masters is running Thursday at the Banzai Pipeline. The third round, quarterfinals, semifinals and final are expected to be completed Thursday in 5- to 8-foot waves.

The Pipeline Masters is the third of three events in the Triple Crown series. Irons won the first contest at Haleiwa Alii Beach, then placed third in the second contest at Sunset Beach.