Murray, however, will be mindful of the fact that he has spent more than seven hours over the past three days dispatching first Radek Stepanek and then Mathias Bourgue, 6-2 2-6 4-6 6-2 6-3.
It certainly wasn't in his plans as he bids for a first French Open title, and it's sure to take a toll when matches, on paper, become tougher in the second week should the second seed get that far.
"You can't continue playing matches like that and then expect to win the tournament," Murray told reporters.
They have proved extremely plenty difficult so far, and surprisingly so, for the man who entered the French Open on the back of a fruitful buildup on the clay.
Completing a win over
Radek Stepanek, bubbly as ever at 37, on Tuesday despite being two points from defeat at one point, Murray was supposed to have a simpler task on Wednesday against the little-known French wildcard.
"It's been a tough, tough few days," said Murray.
Ranked 164th, Bourgue had never played in a grand slam main draw before this French Open and the highest-ranked player he had ever beaten was a 55th-ranked Victor Estrella Burgos earlier this year.
Given the way he was, at times, dictating play against the two-time grand slam winner, Bourgue resembled a Borg -- Bjorn -- the six-time Roland Garros titlist.
When the battle ended, in an extremely rare occurrence, the 22-year-old was interviewed on court. That's usually reserved for winners.
Murray's contest, though, against Stepanek must have taken a greater toll than anticipated. After he cruised in the first set, Murray lost a whopping 16 consecutive points as the second set turned into a third. Double faults missed by a yard and drop shots landed one-third of a way up the net.
When Murray lost the third, he was just a set away from becoming the first top-two men's player to exit to a peer ranked outside the top 160 at a major in over a decade. The last time was when Ivo Karlovic ousted Lleyton Hewitt in the first round at Wimbledon in 2003.
Interestingly, Karlovic is Murray's next rival.
He, too, is bound to be fatigued. Aged 37 like Stepanek, Karlovic beat Australia's Jordan Thompson 6-7 6-3 7-6 6-7 12-10 in four hours and 34 minutes. Karlovic, along with John Isner the tallest man in tennis at 6-foot-11, struck 41 aces and 103 winners as he became the oldest man to reach a grand slam third round since a 38-year-old Jimmy Connors at the 1991 U.S. Open.
Given their efforts, Karlovic and Murray will be pleased to have a day off on Thursday to recover.
Murray had battled an opponent who mixed an aggressive baseline game with deft drop shots. Impressively for a newcomer, Bourgue didn't miss many shots in the second and third. A sluggish Murray awoke to begin the fourth, noticeably lighter on his feet and moving better between shots. The inexperienced Bourgue asked for cola and candy bars to raise his energy levels in the fourth.
He must be watching countryman Gael Monfils, who has guzzled cola the past few weeks during changeovers.
Still, Bourgue -- thankfully for the neutral (not that there were many on center court) -- didn't entirely capitulate in his first-ever fifth set. Trailing 5-1, Bourgue won two games in succession and led 30-15 on the Murray serve but the latter closed out his spirited yet tired opponent, to the crowd's dismay, with a crunching backhand down the line.
Defending champion Stan Wawrinka also labored, though not nearly as much as Murray, in beating Japan's Taro Daniel 7-6 6-3 6-4, having saved two set points in the first-set tiebreak.
Japan's Kei Nishikori, due to face Murray in the quarterfinals, continued to breeze, topping Andrey Kuznetsov in straight sets, and Australia's Nick Kyrgios, another with good results entering the French, swept past Dutch serve-and-volleyer Igor Sijsling 6-3 6-2 6-1, only conceding one break point.
No problems for leading women's seeds
In the women's draw, second-seed Agnieszka Radwanska, fourth-seed Garbine Muguruza, sixth-seed Simona Halep, 10th-seed Petra Kvitova and last year's finalist, Lucie Safarova, all advanced in straight sets, as did 2009 winner Svetlana Kuznetsova and 2010 finalist Sam Stosur.
Murray, for now, is having no such luck.