World number 158 Bethanie Mattek-Sands is into the last 32 of the Miami Open after beating Elina Svitolina 7-5 6-4 in straight sets.
The 32-year-old pulled off an upset to record her first win over a top-10 opponent since 2015, setting up a meeting with Anastasia Pavlyuchenkova in the next round.
Both players struggled to hold serve in the early stages, but it was Mattek-Sands who settled the quickest as she edged a long-running third game by saving five break points.
It was proving to be a tight affair, with Svitolina saving a couple of set points before eventually coming unstuck and falling behind in the match.
A similar tale unravelled in the second as Mattek-Sands continued to fend off her opponent, saving a total of 12 of the 15 break points she faced across the course of the contest.
Ninth seed Svitolina lost serve three times in what proved to be the final set, allowing her American opponent to get over the line to keep her outside hopes of success alive.
