Gauff carried that momentum into the second set with a double break to take a 3-0 lead, continuing to target Vesnina's backhand as the Russian made a slew of errors.
Two-time champion Andy Murray, whose ranking has slipped to 118 as he battles to come back from hip surgery, will be aiming to win gold for the third Olympics in succession.
We reached a general agreement with Manchester United on the transfer of Jadon Sancho, pending full completion, as there are still some formalities to agree on and the medical check to be completed.
England's first success against the Germans in a knockout match for 55 years was secured by late goals from Raheem Sterling and Harry Kane at Wembley on Tuesday