Rafael Nadal matched his best career start to an ATP Tour season with a victory Tuesday in his first match since capturing the Australian Open title, reaching the second round of the Mexican Open.
The 35-year-old Spanish left-hander defeated US lucky loser Dennis Kudla 6-3, 6-2 to book a hardcourt date with American Stefan Kozlov in the last 16.
"It has been a positive start, a good victory in straight sets. That's always very positive for the confidence," Nadal said.
"I played a very solid match, a good effort today. Of course there are a couple of things that I can do better, but in general terms, I played well so I can't complain at all."
The victory lifted Nadal to 11-0 this year, matching his best career start to any season. He also won 11 matches in a row to begin the 2014 campaign before losing to Swiss Stan Wawrinka in an Australian Open final.
Nadal won his men's record 21st Grand Slam title at last month's Australian Open, breaking the career mark of 20 Slam crowns he had shared with Novak Djokovic and Roger Federer.
World number five Nadal broke 100th-ranked Kudla in the fourth game for a 3-1 lead and held from there to claim the first set of their first career meeting.
When Kudla sent a forehand long to surrender the first break of the second set, Nadal seized a 2-1 lead and held at love to 3-1.
Nadal broke again for a 4-1 edge and held twice more, claiming the victory on a forehand winner.
Fourth seed Nadal fired eight aces and won 36 of 40 points on his serve in the dominating outing.
The Spaniard seeks his 91st career ATP title and third of the year, having also won a Slam tuneup tournament at Melbourne.
Russian top seed Daniil Medvedev, the reigning US Open champion whom Nadal rallied past in five sets in the Australian Open final, began his run at the world number one ranking with a 6-3, 6-4 victory over Frenchman Benoit Paire.
"It's always not easy to come back after some rest and some time off competition," Medvedev said. "I felt like my sensations were not at the top today, but I managed to fight until the end against a very tough opponent and I'm happy that I managed to win."
If Medvedev wins the Acapulco title, he is assured of overtaking Djokovic atop the rankings no matter how the Serbian star fares this week at Dubai.
"If Novak would not be playing, then maybe it would be a little bit more in my mind because it would only be me that it depends what I can do," Medvedev said.
Medvedev would become the 27th player to reach world number one and only the third Russian, joining Yevgeny Kafelnikov (1999) and Marat Safin (2000-01).
The last player outside of Djokovic, Nadal, Federer and Britain's Andy Murray to sit atop the rankings was American Andy Roddick in February 2004.
Medvedev will next play Spain's 68th-ranked Pablo Andujar.