Toronto is in the midst of a skyscraper race for the title of Canada's tallest building (no, the CN Tower is not a building) as a pair of contenders duke it out just over three kilometres apart on Yonge Street.

Mizrahi Developments' The One and Pinnacle International's SkyTower will be the first two towers in Toronto and Canada to exceed 300 metres in height, a completely arbitrary mark where, according to the Council on Tall Buildings and Urban Habitat, a skyscraper becomes a "supertall."

The developers have engaged in a back-and-forth of warring egos that has included recent appeals for increases to the towers' already-record-breaking heights.

As it stands now, the SkyTower at 1 Yonge Street has the edge with an approved height of 95 storeys/312 metres and an application to increase that prominence by another ten storeys. If approved, it would be the first in the country to exceed the 100-floor count, holding a staggering height of 345 metres.

The One — rising from the southwest corner of Yonge and Bloor — is also chasing a height increase from its approved 85 storeys/308 metres, seeking approval to instead build the tower to 94 storeys and a 338-metre peak.

The One rising at Yonge and Bloor. Photo by Jack Landau.

SkyTower seems to hold the better hand of the two, but that seems like it probably won't be enough to stop The One from — at least temporarily — laying claim to the title of Canada's tallest building.

The One's structural exoskeleton support system on display. Photo by Jeremy Gilbert.

After a rocky start that included a lengthy construction pause, the behemoth is now steadily rising above Yonge and Bloor, revealing details of its innovative structural exoskeleton and glimpses of its exterior cladding.

Photos captured in mid-April show dark glazing climbing the tower base, along with the first panels of champagne-coloured caps enclosing the enormous exposed structural columns supporting the tower's loads.

First panels of cladding encasing support columns at The One. Photo by Jack Landau.

This unique form of structural expressionism from renowned architecture firm Foster + Partners was designed to create a vast open retail space on the ground floor free of structural columns and elevator shafts.

Facing southwest across the Yonge and Bloor intersection to the future retail space at the base of The One. Photo by Jeremy Gilbert.

This retail space was destined to be Toronto's flagship Apple Store, though rumours have been swirling since last year that the global tech giant may be looking to pull out from the deal due to compounding delays.

New floors are added to the tower roughly every week or so, as the structure now stands at approximately one-third of its approved height.