Belgium is one of Europe's most competitive markets for network quality, as a new metrics report found nothing to separate operators in more than half the categories.
Testing agency OpenSignal's latest research into the market found BASE snatching victory for the best LTE download speeds. It averaged 45MBps, one of the testing company's highest ever download rates in any market.
Proximus was second with 39MBps but there was bad news for Orange, which fell from joint first six months ago to third, with an average download speed of just under 34MBps.
Proximus came away from the report with two awards, for best upload speed and lowest latency.
Its upload speed was 14.36MBps, compared to Orange with 13.08MBps and BASE at 12.73MBps.
OpenSignal described latency as one of the mobile industry's overlooked yet increasingly important metrics due to changing consumer habits.
Proximus' latency was under 30ms, but Orange tumbled from poll position six months ago to second with a latency of 31.24ms.
However, there were three way ties for 3G download speeds and LTE availability, which sat at 85 percent.
Proximus and BASE tied for best overall download speed, and Orange and Proximus were level for 3G latency. BASE improved its overall download speed by 6MBps during the past six months.
OpenSignal described the competition as "close run" but noted this is only set to intensify after the Belgian government said it is looking for a fourth operator to take part in its forthcoming spectrum auction.
OpenSignal made 141 million network measurements across Belgium from more than 10,000 devices in 90 days from 1 May.