Emma Raducanu’s scintillating early run at the Western and Southern Open has ended in a 7-5 6-4 defeat to Jessica Pegula.

The British 10th seed opened her campaign in Cincinnati with impressive victories over WTA Tour veterans Serena Williams and Victoria Azarenka.

But the top-ranked American proved too tough a mountain for the defending US Open champion to climb.

Pegula took control early in the match, dictating ground play and converting two break-point opportunities to clinch the first set.

Another break early in the second then gave world number eight the momentum she needed to secure her place in the quarter-finals.

Pegula’s technical prowess disrupted the clinical tennis Raducanu exhibited in her earlier matches, with the 19-year-old giving up 21 unforced errors in the loss.