Grand champion Hakuho flexed his yokozuna muscles on Wednesday to stay on the heels of a pair of rank-and-filers in the lead after four days of action at the Kyushu Grand Sumo Tournament.

The Mongolian-born veteran was made to work overtime by top-ranked maegashira Okinoumi (1-3), who went toe-to-toe with the yokozuna and had Hakuho teetering at the edge, but eventually fell in an otherwise impressive display at Fukuoka Kokusai Center.

Okinoumi, who went 11-4 and earned a Fighting Spirit Prize at September's Autumn meet, was looking to beat the grand champion for just the second time in 22 career match-ups.

Hakuho, chasing a record-extending 43rd top-division title, joins 11 other wrestlers sitting one win behind No. 10 Shodai and top-division rookie No. 16 Wakatakakage.

(Hakuho (R) and Okinoumi)

Shodai quickly dispatched No. 10 Shimanoumi (2-2) to hold onto his share of the lead, while overnight co-leader No. 9 Yutakayama was steamrolled by No. 8 Sadanoumi (3-1) in his first loss of the tournament.

Wakatakakage remains perfect in his makuuchi debut after driving out No. 14 Terutsuyoshi (2-2), but appeared to land awkwardly on his right leg as his momentum carried him off the dohyo.

The 24-year-old newcomer had trouble walking on his own power and was eventually carted off in a wheelchair, casting doubt on his fitness for the remainder of the 15-day meet.

The scene was reminiscent of Day 2, when Tomokaze sustained a serious right knee injury that saw him join the growing list of withdrawals here. Yokozuna Kakuryu and ozeki Goeido also pulled out with earlier injuries.

(Tochinoshin (L) and Takarafuji)

In other bouts, komusubi Hokutofuji (3-1) provided the upset of Day 4 by defeating ozeki Takayasu (2-2), who needs at least eight wins here to keep his rank.

Hokutofuji took advantage of a weak initial hit and quickly slipped to the side of Takayasu while turning the ozeki around and driving him out.

Takakeisho, the other ozeki still competing, got komusubi Endo (1-3) low with a well-timed arm pull and slapped the fan-favorite down to the sand to improve to 3-1.

Among the sekiwake, Tochinoshin (2-2) got his second straight win by expertly employing a last-second throw against No. 3 Takarafuji (1-3).

(Hokutofuji (L) and Takayasu)

Mitakeumi (2-2), meanwhile, allowed No. 1 Daieisho (2-2) to get two hands on his belt and deposit him over the straw.

New komusubi Asanoyama forced out No. 2 Myogiryu (2-2) to collect his third win, while No. 2 Meisei (3-1) pushed out struggling komusubi Abi (1-3).

In other rank-and-file bouts, division lightweight No. 6 Enho (3-1) continued to impress, keeping No. 7 Kotoeko (0-4) at bay before bulldozing his opponent off the ring.

No. 8 Shohozan (3-1) won a hometown battle with fellow Fukuoka native No. 9 Kotoshogiku, executing a powerful overarm throw after a stalemate to keep the former ozeki winless.

Related coverage:

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Sumo: Hakuho upset on Day 2 of Kyushu meet as title chase blows open

Sumo: Hakuho opens Kyushu tournament on winning note