Having a week full of tennis under its belt, the ATP Masters 1000 event from Miami got its last eight gladiators in men's singles. The 4th round ended with a huge upset as the no. 1 seed Stan Wawrinka collapsed against the young rising star Alexander Zverev. That stirs things up on the upper half of the draw putting Roger Federer one step closer to his 3rd Miami success. The 35-year-old Swiss got past Spain's no.

2 Roberto Bautista-Agut (18 ATP). It was a tight clash having both sets won by Federer after playing two tie-breaks. Bautista-Agut put in some of his finest tennis but at the end that wasn't enough to cause a derailment to the Swiss.

Federer is yet to drop a set against the Spaniard

Entering the clash in Miami's 4th round, Roger Federer had all the assets on his side. In their previous five matches, the Spaniard failed to accumulate a set against Federer. This time, he was the closest as he put both sets to the edge of a tie-break. Still, not enough as Federer kept his cool during the encounter.

For Federer, Tomas Berdych, the no.1 Czech is the next puzzle to sort it out. Berdych and Federer had their last clash back in January at the Australian Open. It was a 3rd round highlight which ended with a three sets triumph for the Swiss. In their head to head stats, the score is 17-6 for Roger. Last time Berdych ousted Federer was a few years back in 2013 in Dubai. The Swiss player won their last six meetings which give him a significant upper hand against the Czech.

Federer on a collision course with the ATP newest stars

If he gets past Berdych, Federer will play against either Nick Kyrgios or Alexander Zverev. Both players are starting to make a name for their own at the top of the ranking.

Zverev put Wawrinka on the sideline at the end of a tremendous comeback for the young German. On the other side, Kyrgios dismantled David Goffin in straight sets. This Zverev vs. Kyrgios duel is likely to become a serious rivalry over the next years. At Indian Wells, it was Kyrgios who left Zverev with no response. If the outcome is the same, then Kyrgios will have his revenge over Federer. In California, the young Aussie was set to face Federer but was forced to withdrew due to a food-poisoning case.