Symmetra's Teleporter frequently leads to the most interesting and funny ability combinations in Overwatch, with the infamous teleporting Self-Destruct being the most iconic in its history. This trick might be even better.
Mista-fish, playing Reinhardt, approaches first point Hanamura with their team at the start of the last push of the game. The score is tied 2-2, and if mista-fish and company earn even a single tick on the first point they'll win the match.
The team lines up at the chokepoint, but rather than try to push through the enemy team, their Symmetra lines up a Teleporter that leads directly onto the point. The whole team files through while mista-fish holds shield to protect them. Mista-fish is the last player through the portal, and when they step through they find their teammate, playing Mei, has already put up an ice wall to block the entrance to the point.
The capture progress fills, and before the enemy team even makes it to the point mista-fish's team hits that first tick and wins the match. Clean.