Danielle Collins boosted her hopes of winning a title in her farewell season as the unseeded American beat French 23rd seed Caroline Garcia 6-3 6-2 on Wednesday to reach the Miami Open semi-finals.

Collins, who announced in January that she would retire from professional tennis at the end of this season, won 89.7% of her first serve points against Garcia, never faced a break point and converted three of her eight break-point chances.