TOKYO, July 31 (Reuters) - Japan's Nikkei share average reached a four-week high on Monday, as a calm bond market following the Bank of Japan's surprise policy tweak and growing optimism from a slowing of U.S. inflation boosted investor sentiment.

Earnings reports also produced some standout winners, with Toyota Group's logistics company Toyota Tsusho surging almost 10% and helping lift the auto sector.

The Nikkei gained 1.26% to 33,172.22, and was up as much as 2% earlier in the session, while the broader Topix gained 1.39% to 2,322.56.

Of the Nikkei's 225 components, 191 rose and 34 fell.

The BOJ "has maintained easy monetary policy for now, so recent uncertainty has receded, which I think has provided a major reassurance for the market," said Masahiro Ichikawa, chief market strategist at Sumitomo Mitsui DS Asset Management.

"Today will probably be the high for this week. Since policy accommodation hasn't strengthened, a continued weakening of the yen and rise in stocks seems unlikely."

On Friday, the BOJ kept stimulus settings unchanged but announced it would conduct bond buying operations at a yield of 1% instead of the official 0.5% ceiling under its yield curve control.

The benchmark Japanese government bond yield rose to a nine-year high of 0.605% to start Monday trading, but failed to push above that as the central bank conducted additional purchase operations to slow its rise.

Japanese stocks also got a lift from Friday's Wall Street rally, after data showed U.S. inflation rising at the slowest pace since early 2021.

Precision machinery was the best performing of the Tokyo Stock Exchange's 33 industry groups on Monday, gaining 3%. Transport equipment was a close second, rising 2.83%.

Toyota Motor rallied 3.29% and Toyota Group supplier Denso added 3.76%.

Other notable winners included Uniqlo parent Fast Retailing and chipmaker Renesas Electronics, up 1.98% and 4.59%. respectively.

At the other end, Sumitomo Pharma tumbled more than 10% after disappointing trial results for its schizophrenia treatment, while robot maker Fanuc lost 7.27% after earnings disappointed. (Reporting by Kevin Buckland; Additional reporting by Nobuyo Saito; Editing by Nivedita Bhattacharjee and Varun H K)