#4 Borna Coric, Halle Open & Shanghai Masters
Coming off the high of winning the Stuttgart Open, Federer also made the final of the last event in the run-up to Wimbledon - his favourite hunting ground, Halle.
In the first set he missed a break point in Game 10, after which he had a couple of set points in the tiebreak. But he let them both slip and Borna Coric won four points in a row to clinch the set.
Federer came right back, overcoming a bit of pressure on serve in Game 3 to eventually break in the 8th. He served the set into his pocket to take the match into the decider.
The third set seemed equally poised with Coric serving at 2-all, but something clicked him into overdrive and he won four straight games to complete a memorable upset.
The semifinal at Shanghai was a much easier affair for the Croatian. That tournament saw a marked improvement in his backhand and serve, and Federer had no answer.
The Swiss was broken in the first game of each of the two sets and didn't look like coming back at any stage. Coric won 21 points off the Federer serve and didn't concede even a single break point on his own serve.
Not too many people can upset Roger Federer twice in a year, can they?
Who Are Roger Federer's Kids? Know All About Federer's Twins