TOKYO, Sept 10 (Reuters) - Japan's Nikkei average closed at a 5-1/2-week high on Tuesday as companies expected to benefit from the 2020 Summer Olympics kept drawing retail investors, while positive leads from global markets and China data boosted sentiment. The benchmark Nikkei rose 1.5 percent to 14,423.36, a level not seen since Aug. 2. The broader Topix also advanced 1.5 percent, to 1,190.22, with trading volume at a three-month high of 4.23 billion shares. The construction sector climbed 5.1 percent and was the biggest sectoral gainer. Taisei Corp soared 13.2 percent and was the most-traded stock by turnover on the main board.