Andy Murray reached the last 16 of the BNP Paribas Open in Indian Wells despite looking far from his best.
Fourth seed Murray, who defeated Andreas Seppi of Italy on Sunday after receiving a first-round bye, again struggled with his service against world No.68 Michael Russell but eased through the third-round clash 6-3 7-5.
The 22-year-old from Dunblane will now play either Nicolas Almagro or James Blake in the next round.
Murray broke in the American's first service game, but his own delivery was floundering with a first-serve percentage at a paltry 40 percent after three service games.
He broke Russell in the ninth game to take the first set in 40 minutes with something to spare.
Murray broke Russell comfortably and fought a break-back point to go 3-0 up in the second.
Russell was scampering around the court in determined fashion and secured a first break as Murray was attempting to close out the match to bring the second set back on serve.
But the Briton earned two match points in Russell's next service game and needed only one of them to earn a straight-sets win in one hour 52 minutes.
"He made it difficult for me," Murray told Sky Sports 4.
"He hits a solid ball from the back of the court, he plays very close to the baseline and obviously he's very quick."
"He's got a great attitude, fights really hard and made it difficult."
Elsewhere, sixth seed Robin Soderling saw off Feliciano Lopez in two tough sets, eventually winning 7-6 (7-3) 6-4.
Lopez, seeded 28th, stayed with his opponent despite not earning a break point in the entire match.
Austrian Jurgen Melzer, seeded 22, also progressed after German Simon Greul pulled out prior to their match with illness.