British number one Kyle Edmund beat his compatriot Dan Evans 1-6 6-3 6-4 to reach the semi-finals at Eastbourne.
British number three Evans, 29, showed the form that has brought him two grass-court titles this month as he dominated the first set.
But Edmund fought back to give himself a confidence boost as he seeks to regain his best form before Wimbledon.
Edmund, 24, will face Taylor Fritz on Friday after the American defeated Poland's Hubert Hurkacz 6-4 7-6 (7-5).
World number 65 Evans broke Edmund's serve in the opening game and followed it up in the fifth as he used his backhand slice to keep his compatriot's powerful shots at bay.
Edmund, who retired from the French Open last month with a knee injury, could not get into the match and conceded the first set when he blasted a forehand wide.
In the first set Edmund won 44% of points on his first serve but he turned it around with 100% in the second.
That extra power and precision had Evans struggling to return the ball with the same quality and gave Edmund the chance to assert himself.
Having levelled the match, Edmund kept up the intensity in the decider and, with Evans becoming frustrated with his inability to counter his opponent's power, the world number 31 sealed victory with his fourth match point.
In the other semi-final, American Sam Querrey beat fifth seed Fernando Verdasco 7-6 (7-4) 6-2 and will play Italian Thomas Fabbiano, who defeated Queen's Club runner-up Gilles Simon 6-4 6-3.