Novak Djokovic banged his racquet against the soles of his shoes trying to shake free clumps of red clay that clogged the treads. On a wet day of shaky footing, Djokovic hit through the tricky conditions and Joao Sousa, 6-1, 6-2, 6-4, to reach the second round of the French Open.

The match was twice interrupted by rain delays as the crushed red brick court turned soggy in spots, and heavy conditions placed a premium on controlled depth. Djokovic moved fluidly and changed direction shrewdly, slashing his backhand down the line to scar Sousa, and he even engaged the crowd with some levity. During a late second-set rain delay, the second seed invited the ball kid holding the umbrella over his head to take a seat next to him—then they shared a Perrier toast and a chat, gazing at the court like two picnickers in a park waiting for the weather to break.

There was no shelter for Sousa at the start, as Djokovic came out hitting heavy, deep drives, and converted his fourth break point for a 2-0 lead. He backed up the break at love.

The drizzle escalated into a steadier rain, making the lines slick as Sousa broke back for 1-4. The players left the court for the shelter of the locker room at 2:30 P.M. local time. Play resumed after about a 72-minute rain delay.

Playing with the urgency, Djokovic scored his third straight break for 5-1, only to fall into a triple-break point deficit when serving for the set. But he hit right out of that hole, twisting a slice serve down the T to seal the opening set after saving each Sousa chance.

The cumulative pressure of Djokovic's corner-to-corner strikes left Sousa both breathless and a bit shell-shocked as he double-faulted to donate a break and cede a 3-2 second-set advantage. A slick down-the-line forehand pass followed by a smash earned Djokovic a second straight break and 5-2 lead as the rain picked up its pace. Djokovic plopped down on his court-side seat wearing a white hoodie, while coach Boris Becker, making no concession to the precipitation, sported black aviator shades in the coaching box.

Serving for a two-set lead, Djokovic saved two break points—the first with a reflex backhand winner down the line and second with a sharp inside-out forehand winner—and zapped his seventh ace down the middle to snatch a two-set lead.

Given that Sousa arrived in Paris on a seven-match clay-court losing skid, carried collateral damage from the 6-0, 6-2, 6-2 pounding Djokovic dished out at Flushing Meadows last summer, and he slammed his racquet off the side of his head in frustration after falling behind 4-1 in the third, all signs pointed to the first Portuguese man to win an ATP title packing it in at that point. To his credit, Sousa began smacking his forehand down the line, broke twice in succession, then held at love for 4-5.

Djokovic quelled that two-game uprising, slamming his ninth ace and 40th winner to set up a second-round match with Jeremy Chardy. The Serb probably won't be satisfied with the muddied patch of play near the end, and he overplayed the drop shot a couple of times, but he was a sniper on return, winning 77 percent of Sousa's second-serve points and breaking eight times in scoring his sixth straight win.