In Boulter and Raducanu, Britain have pedigree which ranks among the most substantial in the competition.
British number one Boulter, who has moved into the world’s top 25 after a season in which she won two WTA titles, was the third-highest ranked singles player left in the quarter-final stage.
Former Grand Slam champion Raducanu also ranked third among the number two players.
So, while reigning champions Canada are second in the world, there was no reason for Britain to have an inferiority complex going into the best-of-three tie.
The presence of Gaby Dabrowski – the doubles world number three and recent WTA Finals champion – did mean a deciding doubles was not where Britain would have particularly relished going, however.
Therefore, it felt imperative that Raducanu opened with a win.
The first set, with a huge gulf of quality between the her and 103rd-ranked Marino, required ruthlessness.
The second asked for patience and resilience. Raducanu was forced to save seven break points before taking Marino’s serve in the 11th game.
“It was an incredibly difficult match because the dynamics were so different in each of the sets,” said Raducanu.
Raducanu, who has now won her past four singles matches for Britain, laid the platform for Boulter to seal the deal against 31st-ranked Fernandez.
Playing on a fast hard court which suits her excoriating style, Boulter ran away with the first set when Fernandez’s service game disintegrated with a flurry of double faults.
The confidence of Boulter, built up over the finest season of her career and maintained in a team environment in which she thrives, carried into the second set.
Surging into a 4-0 lead moved her on the verge of victory before nerves kicked in.
Boulter failed to serve out victory at the first time of asking, walloped a forehand long on a match point on Fernandez’s serve at 3-5 and then produced a double fault on her second match point.
But, with the vocal British support trying to rally her, she managed to get over the line at the fourth attempt to spark jubilant celebrations among the Union Jack-clad contingent.
