Norway’s Casper Ruud, ranked fourth in the world, had to work hard to beat Argentina’s Sebastián Báez 6-3, 1-6, 6-3 when he entered the clay-court tournament in Hamburg on Wednesday.

A little earlier, the Russian Andrey Rublev, seventh in the world and seeded N.2 behind Ruud, also struggled to dismiss the Spaniard Bernabé Zapata 5-7, 6-1, 7-6 (9/7) in a decisive tie-break.

Tournament favourites, the two players met in the final in Bastad (Sweden) last week, with Rublev winning in straight sets.