The Celtics and Bruins are no longer the only games in town in the West End.

The first two phases of The Hub on Causeway, Boston Properties’ and Delaware North’s more than 1.5M SF mixed-use project adjacent to the TD Garden, opened Wednesday. Construction is still underway on the third phase of the project, a 630K SF office building that has Verizon signed as an anchor tenant.

“What we see before us today is exactly the kind of transit-oriented development that we always envisioned for this area,” said Charlie Jacobs, Delaware North’s CEO of Boston Holdings, in a statement.

Boston Properties manages all the development of The Hub on Causeway, while Delaware North owns and operates the TD Garden.

The Hub on Causeway project’s first and second phases include a 145K SF office — now home to software company Rapid 7’s headquarters —  the 38-story Hub50House apartment tower, a 60K SF Star Market grocery, a 270-room CitizenM hotel and the ArcLight Boston movie theater.

TD Garden was expanded by 64K SF as part of the project. A 10K SF outdoor space serves as the new entrance to the arena, and an underground pedestrian tunnel was built between the subway and commuter rail components of North Station. Passengers had to previously exit the station and walk outside to make connections between the two rail links.

The 31-story office tower is expected to complete in 2021, when Verizon is expected to occupy 17 stories.

“The Hub combines the best of Boston’s sports, dining and live music as well as provides jobs and housing at the northern gateway to the city,” Boston Properties Executive Vice President Bryan Koop said in a statement. “We are thankful for the City of Boston’s continued support of our vision to create an urban village at The Hub.”