Fifth seed Daniil Medvedev brushed off an ankle concern and booked his spot in the Indian Wells Open semi-finals after a straight-sets win over Alejandro Davidovich Fokina on Wednesday.

The 2021 US Open champion triumphed 6-3 7-5 over the Spaniard in one hour and 44 minutes, securing his 18th straight victory.

Medvedev will face Frances Tiafoe in the semi-finals after the American beat Briton Cameron Norrie 6-4 6-4 in the other quarter-final in that half of the draw.

The Russian had suffered an ankle injury during Tuesday's last-16 win over Alexander Zverev but played on to clinch a hard-fought three-set win.

But Medvedev alleviated any injury concerns, although he required treatment on a bloody right thumb in the second set while escaping from 0-40 at 3-4.

"I'm actually happy the ankle didn't hurt much because when I warmed up, it was hurting pretty bad," Medvedev said post-match.

"I knew I was going to play, I knew I was going to try. But I couldn't move well on the warm-up. I tried to warm it up as long as possible, took one painkiller so that probably helped. I was actually feeling better and better during the match."

Medvedev raced to a 3-0 lead in the first set and never looked back, although Davidovich Fokina fought hard in the second frame but missed his big chance in the eighth game.

The pair both hit 24 winners for the match, but the Spaniard's 24 unforced errors compared to Medvedev's 12 was a key difference.

Tiafoe, who made last year's US Open last four, awaits after needing only one hour and 25 minutes to eliminate 2021 Indian Wells champion Norrie and reach his maiden ATP Masters 1000 semi-final.

Norrie had been on an eight-match winning run but the American hit 22 winners and only gave up nine unforced errors.