Novak Djokovic came through a tough test against Kei Nishikori on Monday to reach the second round of the 2018 Madrid Open.
The two-time former winner beat Nishikori 7-5, 6-4 in their first-round clash, the pair going head-to-head for just shy of two hours before Djokovic prevailed.
In the women's draw, Maria Sharapova reached the third round with a hard-fought 7-5, 6-1 triumph over Irina-Camelia Begu.
Meanwhile, second-seed Caroline Wozniacki was taken to three sets by Ashleigh Barty but eventually prevailed 6-2, 4-6, 6-4.
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Djokovic, 30, is still not back at his very best, but he showed flashes of his former greatness against Nishikori.
Alongside the brilliance, though, there were uncharacteristic mistakes, noticeably an unforgivable missed overhead in the second set that, fortunately for the Serbian, didn't come back to haunt him.
It was a matter of Djokovic taking his opportunities at just the right times.
After the opening exchanges saw him and Nishikori trade a break each for 3-3, the 12-time Grand Slam winner then pounced on the Japanese player's serve at 6-5 ahead, taking the set with a forehand winner.
The second set was even tighter. Both players offered up just one break point apiece, but again Djokovic took his advantage when he needed to.
He played a very fine game as Nishikori served at 5-4 down to stay in the match, and after earning a match point with a brilliant driving backhand down the line, Djokovic then claimed the victory when his opponent went long.
Per Tom Perrotta of the Wall Street Journal, it was one of Djokovic's best recent performances:
Before arriving in Madrid, Sharapova had been knocked out of three successive tournaments in the first round.
She finally broke the run with a straight-sets defeat of Mihaela Buzarnescu on Sunday and is now into the last 16 in Spain.
Begu, 27, provided a serious challenge for the five-time Grand Slam winner, going a break up in the opening set.
However, Sharapova then levelled for 3-3 before breaking again to take the first set after more than an hour.
She then rattled through the second set, earning three breaks to book her spot in the last 16, where she will face Kristina Mladenovic.