Igor Sijsling defeated De Bakker, his Dutch countryman, 4-6, 6-2, 7-6 (7-4). Sijsling was able to convert three of his seven break-point chances and didn't drop serve himself after the first set.
Henri Kontinen also advanced by winning a third-set tie-breaker, beating Dustin Brown 7-5, 2-6, 7-6 (7-5). Brown had the edge in aces (14-9) and service breaks (4-3) but most of those advantages came in the second set while Kontinen was able to hang on and take the tie-breaker.
Also Monday, Daniel Brands stopped Rameez Junaid 6-1, 6-3; Xavier Malisse won 6-3, 6-2 over Rajeev Ram; and Arnaud Clement got by Simon Stadler 6-1, 3-6, 6-1.
The grass-court UNICEF Open is the final tuneup for next week's tournament at Wimbledon.