The silver medallist at last year's worlds has 7,477 points with just the javelin and 1,500 metres remaining on Saturday evening.
Leo Neugebauer (23) of Germany is second on 7,282 points and Olympic champion Damian Warner (33), who is making a bid for a first world title after taking the silver in 2015 and bronze in both 2013 and 2019, is third with 7,260.
LePage began the day in second place behind Neugebauer before moving into the lead with a personal best time of 13.77 seconds in the 110 metre hurdles. He then built on his lead with second-best results in both the discus (50.98 metres) and pole vault (season's best 5.20).
Neugebauer, who in June broke the US collegiate record to win the NCAA championships, struggled in the hurdles but climbed back to second after clearing 5.10m in the pole vault.
Warner's 4.90m in the pole vault was a personal best and kept him in the medal mix. His world championships last year ended abruptly when he pulled up in the 400m with a hamstring injury.
World record holder Kevin Mayer (31) of France withdrew after the first two events due to an Achilles injury suffered two week ago.