GERMAN world number 57 Daniel Altmaier has caused a massive first round boilover in the ATP 500 Abierto Mexicano Telcel yesterday. In a match that lasted two hours and 27 minutes, Altmaier took down top seed and countryman Alexander Zverev in three sets, 6-3 3-6 6-3.

Though Zverev lead the head-to-head 2-0 coming into the match, Altmaier played some outstanding tennis in his first clash with the world number six outside a Grand Slam. The 25-year-old won less percentage of points off his serve (75 and 50 per cent compared to 76 and 59 per cent), but broke twice from three chances. By comparison, Zverev could only break once from seven opportunities.

Both players hit identical winners ad unforced errors in the match with 22 and 15 respectively, with Zverev marginally shading Altmaier in total points won (80 to 78). Despite that, held his own and produced nine aces to Zverev’s eight and showed he could match it with the player regarded as the Tour’s best server.

The win was Almaier’s first against a top 10 player on a hard court, and fourth overall. He was the only unseeded player to knock off a seed on the opening day, with second seed Holger Rune and fifth seed Stefanos Tsitsipas cruising through in straight sets. Sixth seed Casper Ruud and eighth seed Frances Tiafoe also found their assignments a little tougher, grinding past Christopher Eubanks and Max Purcell respectively in three sets.

It was not a great day for the Aussies with both Purcell and the in-form Jordan Thompson going down. At a career-high 32nd in the world,. Thompson struggled against American qualifier Aleksandar Kovacevic in two hours and 41 minutes, going down 6-3 5-7 6-4. The Aussie was only able to convert two of 11 break point opportunities despite playing pretty well with 33 winners and 16 unforced errors compared to Kovacevic’s 20 and 14 respectively.

In other results, German Dominik Koepfer and Serbian Dusan Lajovic both advanced through to the Round of 16. They joined talented unseeded pair Matteo Arnaldi and Jack Draper in the Round of 16 after the duo knocked off American seeds Taylor Fritz and Tommy Paul. The Round of 16 got underway a couple of hours ago.