Watch LIVE track and field coverage on NBCOlympics.com and the NBC Sports app.
Event #3 - Shot Put
Damian Warner did enough in the shot put to maintain his big overall lead, but it was another Canadian, Pierce LePage, to get the best of the top contenders in the decathlon's first throwing event.
LePage tossed his second attempt 15.31m (50 ft, 2.9 in) for 809 points, 32 more than teammate Damian Warner, who hurled an 11th-best 14.80m in his third attempt.
The shot put was won outright by Belarusian Vitali Zhuk with a 16.23m put. Zhuk finished 16th and 21st in the 100m and Long Jump, respectively.
American Garrett Scantling mustered the second-best throw of the round to move into the top five overall.
TOP 5 AFTER SHOT PUT (3/10)
Damian Warner (CAN) - 2966
Pierce LePage (CAN) - 2773
Ashley Moloney (AUS) - 2741
Kevin Mayer (FRA) - 2662
Garrett Scantling (USA) - 2647
Event #2 - Long Jump
Damian Warner delivered a massive leap of 8.24m (27 ft, 0.4 in) — nearly a half-meter farther than any other competitor in the event — to extend his decathlon lead to 206 points through 20% of the competition.
Canadian countryman Pierce LePage followed up his third-place 100m performance with a the runner-up mark in the long jump at 7.65m. However, Australian Ashley Moloney maintained his second position overall with a jump just one centimeter shorter than LePage's.
France's Kevin Mayer, the world record holder, secured the fifth-best mark to climb up into the fourth spot overall.
TOP 5 AFTER LONG JUMP (2/10)
Damian Warner (CAN) - 2189
Ashley Moloney (AUS) - 1983
Pierce LePage (CAN) - 1964
Kevin Mayer (FRA) - 1898
Felipe Dos Santos (BRA) - 1861
Event #1 - 100m
Canada's Damian Warner, the Rio 2016 bronze medalist and owner of the fifth-best decathlon score of all time, got off to a flying start in Tokyo with a time of 10.12 in the 100m, good enough for 1066 points and the early lead.
Warner won Heat 3, which also included the four next fastest times of the three-heat event. Australia's Ashley Moloney finished second to Warner in 10.34, worth 1013 points. No other athlete eclipsed the four-digit mark in the first of 10 events.
Kevin Mayer, the decathlon world record holder from France, finished second in Heat 1 in 10.68, ninth fastest overall. He has fought knee and Achilles injuries over the past two years which have sapped some of his explosiveness.
TOP 5 AFTER 100m (1/10)
Damian Warner (CAN) - 1066
Ashley Moloney (AUS) - 1013
Pierce LePage (CAN) - 992
Zach Ziemek (USA) - 963
Felipe Dos Santos (BRA) - 956