Andrey Rublev needed almost two hours but his punishing forehand helped him to victory over Diego Schwartzman in the San Diego Open quarter-finals on Friday.

Top seed Rublev won 6-1 7-5 in one hour and 52 minutes over the Argentine, who kept on coming throughout the contest.

The Russian world number five's victory books his spot in the last four where he will face Briton Cameron Norrie, who upset fourth seed Denis Shapovalov 6-3 6-1.

Rublev is featuring in his eighth semi-final of the calendar year and chasing his first title since winning in Rotterdam in February.

He had been a break up in the second set after dominating the first, but Schwartzman broke back.

The second set appeared destined for a tie-break with Schwartzman up 40-0 on serve at 5-6, before Rublev won the next five points to claim victory.

"The second set was very tough and enjoyable for the spectators to watch," Rublev said. "Every game was really tough with amazing points and the set could have gone either way."

Second seed Casper Ruud defeated Lorenzo Sonego 6-1 6-4 to book his semi-final spot where he will meet Grigor Dimitrov who beat Aslan Karatsev in three sets.

Ruud's win improved his 2021 record to 45-12, with the 22-year-old Norwegian rising to a ranking of 10.