Roger Federer was making his return to action, as he battled Taylor Fritz in the second round of the Mercedes Cup. The Swiss had not played in more than a month after dealing with a back issue -- and the 17-time grand slam winner, looked like a player just getting back from injury. And a rain delay during the match did not help his rhythm either.
The Swiss Express playing in Stuttgart for the first time since 2001.

Up a break in the opener, Feds is able to get the lovely drop shot for a winner, as he takes the opener 6-4.

The 18-year-old American opponent would grab the second set, and would be serving to stay in front in the decider, but the former world number one unleashes this passing shot.

The Artful Roger would be able to get a late break and is serving for the match --- and seals victory with a blistering cross-court backhand winner. The 17-time Grand Slam champs wins it 6-4, 5-7, 6-4 and meets Germany's Florian Mayer in the quarters.

Austrian earns second straight victory over Australian

That is Dominic Thiem, the Austrian coming off a semi-final performance at the French Open -- and would play Sam Groth of the Australia for a spot in the Last Eight.

The world number seven would be able to stay on server in the opener thanks to this wicked passing shot up the line. The Austrian would take the frame in a tie-break.

The second set, was also close, and Thiem again is able to get a winner with Groth at the net. this set also needed a tie-break.

And in the extra session -- it was the Austrian that would prevail thanks to the ace -- he is off to the quarters. It is the second straight win for Thiem over Groth.

Wild card grabs second straight victory to reach Last Eight

That is Juan Martin del Potro serving to Australia's John Millman. And the Argentine smashes home this winner to take the opening set 6-4.

Second set and Millman facing triple break point, and unfortunately he slips on this point, as the former U-S Open champ fires a winner into the open court and grabs a 5-4 lead.

And the wildcard would be able to seal out the match in the next game, as he fires the forehand winner into the corner. Del Potro wins it 6-4, 6-4 and meets fourth-seed Gilles Simon in the quarters.