Ivo Karlovic stunned Obi UAE Royals star Roger Federer to hand Philippine Mavericks a narrow 26-24 victory on the opening day of the International Premier Tennis League (IPTL) at the Dubai Tennis Stadium on Monday.

IPTL-debutant Karlovic slammed five against Federer's four to win the decisive set 6-4 after both teams were tied at 20-all.

“It was a tough match today. We got off to a good start. We looked good there for a while. But the mixed doubles ran away with it. And in the singles, I always knew it would be a tough match, he’s a tough guy to play against, especially against him, and in this format, where things can turn around very quickly. But I loved it. I had a good time,” said Federer who has lost all four matches in the tournament so far.

"It’s a quick format, anything can happen. The pressure in the IPTL is different. You are playing with less pressure, you are not playing for ranking points, but there is pressure still. You have 5-6 guys sitting on the bench, motivating you … you want to do well for them, you want to do well for the team, you want to do well for the fans. So the pressure never really leaves," said the Swiss legend.

On his match-up against Andy Murray Tuesday, Federer said, “Against Andy I’ve had some great matches. We match-up well, so one can expect a lot of slices, serve and volleys, some coming in, the court plays different than the tournament, definitely slower, so we’ll probably see a bit more rallies."

In the earlier match, Micromax Indian Ace bounced back to defeat bottom team Legendari Japan Warriors 25-18 after Sania Mirza and Rohan Bopanna went down 4-6.

Coming in for the penultimate leg of this five-team competition with the best record of six wins from seven, the defending champions rolled over their opponents.

Playing for the first time together, Kirsten Flipkens and Pierre-Hugues Herbert took their chances and managed the only break of the match in the third game on Mirza’s serve to give the Japanese the lead at 6-4.

Agnieszka Radwanska outgunned Mirjana Lucic-Baroni 6-1 while Fabrice Santoro outclassed Thomas Enqvist 6-0.

Bopanna and Ivan Dodig then team up to win 6-5 against Leander Paes and Herbert.

Results

Micromax Indian Aces bt Legendari Japan Warriors 25-18: Mirza/Bopanna v Flipkens/Herbert 4-6; Radwanska v Lucic-Baroni 6-1; Santoro v Enqvist 6-0; Bopanna/Dodig v Herbert/Paes 6-5; Tomic v Kohlschreiber 3-6.

Philippine Mavericks bt Obi UAE Royals 26-24: Ivanisevic v Blake 5-6; Mladenovic v Tomljannovic 6-2; Mladenovic/Cilic v Gajdosova/Roger-Vasselin 5-6; Cilic/Federer v Huey/Roger-Vasselin 4-6; Federer v Karlovic 4-6.

Fixtures

December 15: (4 pm) Philippine Mavericks vs Micromax Indian Aces; (7.30 pm) Obi UAE Royals vs Oue Singapore Slammers