Alexander Zverev underlined his credentials as one of Rafael Nadal's main challengers at the French Open with a ruthless defeat of Ricardas Berankis in the first round. 

The German, a champion on the clay in Madrid and Munich already this year, saw off the world number 92 in straight sets, 6-1 6-1 6-2, on Suzanne-Lenglen court. 

Zverev was beaten in three tough sets by Nadal in last week's Internazionali d'italia final and showed just why he is among the favourites to challenge the Spaniard's Roland Garros supremacy on Sunday. 

The 21-year-old took an early break with a fearsome backhand down the line and never looked back, firing in 29 winners – including one sublime drop shot – to just 15 unforced errors. 

Berankis struggled to live with the speed of Zverev's serve and ground strokes, taking just two games and mustering four winners across the first two one-sided sets. 

The Lithuanian rallied in the third, a backhand return winner giving the crowd something to cheer at 1-4, but he could not make any further inroads on a Zverev serve that brought about 11 aces and no double faults. 

He did at least claim a fourth game off the number two seed before firing a simple backhand into the net to gift Zverev the win in just one hour and nine minutes. 

Zverev will face Jiri Vesely or Dusan Lajovic in round two.