Jack Sock earned a first-round upset win over last week's champion in San Jose, Milos Raonic, to highlight Wednesday's play at the $1.212 million U.S. National Indoor Tennis Championships.

Sock downed the second-seeded Canadian slugger, Raonic, 6-3, 5-7, 7-5 at The Racquet Club of Memphis.

Raonic had lost in the last two Memphis finals, including one at the hands of Austrian Jurgen Melzer last year.

The sixth-seeded former world No. 2 Tommy Haas defeated Russian Evgeny Donskoy 7-6 (8-6), 6-4 on Day 3. The oft-injured German titled here back-to-back in 2006 and 2007.

Also on Day 3, former world No. 1 and two-time Grand Slam champion Lleyton Hewitt saved two match points before overcoming Taiwan's Yen-Hsun Lu 2-6, 7-6 (7-3), 6-4, No. 7 seed Alexandr Dolgopolov downed Bjorn Phau 6-3, 6-4, Marinko Matosevic took out Go Soeda 7-6 (8-6), 6-4 and American qualifier Donald Young was leading Xavier Malisse 5-1 in the first set when the Belgian retired.

The 2013 Memphis champ will claim $291,800.